EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE

CERN - TS Department

EDMS Nr: 842110 TS-Note-2007-005

Chemical and radiolytical characterization of perfluorocarbon fluids used as coolants for LHC experiments

Radiolysis effects in perfluorohexane fluids

S. Ilie, R. Setnescu, B. Teissandier

Abstract Perfluorohexane fluids, used as coolants within High Energy Physics Detectors in the Large Hadrons Collider (LHC) at CERN, were irradiated using gammas 60Co and characterized using different analytical techniques. The aim of this work was the assessment of radiation induced effects as a function of the chemical nature of these fluids and their impurity content. Were evidenced the radioinduced polymers and acidity, as well as different chemical by-products. Purification tests and measurements were carried out on different irradiated fluid samples to assess the efficiency of such purification treatments in view of their re-use in the HEP detector cooling systems.

April 2007

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TABLE OF CONTENTS

1. INTRODUCTION ...... 1 2. EXPERIMENTAL...... 2 2.1 Experimental details...... 2 2.1.1 Irradiated perfluorocarbons ...... 2 2.1.2 Irradiation doses...... 2 2.1.3 Irradiation conditions...... 3 2.1.4 Analysis methods...... 4 2.2 Radiation induced effects...... 6 2.2.1 Generalities on the fluorocarbons radiolysis...... 6 2.2.2 Radiation induced acidity and the fluorine ions appearance ...... 8 2.2.3 High molecular weight molecules ...... 8 2.2.4 Low molecular weight products (LMwPs)...... 15 2.2.5 Correlation between the literature and the experimental data; qualitative and quantitative radiolytical effects.... 22 2.3 Purification of perfluorocarbon fluids...... 25 2.3.1 Purification of the as received fluids...... 25 2.3.2 Purification (cleaning) of the irradiated fluids types...... 26 3. CONCLUSIONS...... 29

ANNEX 1 - Pressure, acidity and fluorine ions content values for the irradiated perfluorocarbon samples...... 32 ANNEX 2 - Pre-polymer content values for the irradiated perfluorocarbon samples...... 33 ANNEX 3 - GC-MSD chromatograms of the gas phase of irradiated PP1...... 34 ANNEX 4 - GC-MSD chromatograms of the PF 5060 DL...... 38 ANNEX 5 - GC-MSD chromatograms of PF 5060 irradiated fluid...... 43 ANNEX 6 - GC-MSD chromatograms of the purified PF 5060 irradiated fluid ...... 51 ANNEX 7 - FT-IR spectra of the radioinduced pre-polymers ...... 55 ANNEX 8 - Mass evaluation of the radiation-induced deposits on the metallic strips surface...... 60 ANNEX 9 - Optical (visual) inspection of the irradiated metallic strips ...... 61 ANNEX 10 - SEM and EDX inspection of the irradiated metallic strips ...... 66 ANNEX 11 - Perfluoroisobutylene properties...... 75 ANNEX 12 - Carbonyl fluoride properties ...... 78 ANNEX 13 - Purification tests on the as received PF 5060 fluid ...... 80 ANNEX 14 - Purification tests on the irradiated fluids...... 85 ANNEX 15 - FT-IR spectra of irradiated and of purified fluids ...... 105 ANNEX 16 - Thermal behavior of the radiation induced pre-polymer in PF-5060-28 fluid ...... 112

- 1 -

1. INTRODUCTION The previous work [1] was dedicated to the chemical characterization of the perfluorocarbon fluids received in CERN and to the quality control and the compliance tests. Were applied adequate methods for chemical characterization of these fluids; the obtained results confirmed the results from independent tests and confirmed also the validity of the laboratory procedures and methods settled-up [2 - 5]. This report deals with the investigation of the radiation-induced chemical effects (acidity - mainly HF, polymer & pre-polymers, new molecules, etc.) in perflurocarbon fluids of interest for CERN cooling applications (Table 1). These fluids were chemically characterized [1] and it was found that PP1 (F2 Chemicals, UK), PF 5060 DL (3M, USA) and C3F8 (ASTOR, RU) as received, met the CERN requirements [6]. The expected doses are roughly in the range of 40 Gy to 30 kGy, depending on the cooling application (Table 1) [7].

Table 1 – Irradiation doses expected for cooling fluids in various LHC Experiments [7]

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Experience Detector Fluid (Gy) (Gy) (Gy) (Gy) (Gy) (Gy) (Gy) (Gy) (Gy) (Gy) SCT ATLAS C F 40 240 1240 5240 9240 13240 17240 21240 25240 29240 Evaporative 3 8 ATLAS TRT C6F14 3 18 118 418 718 1018 1318 1618 1918 2218 ATLAS Cables C6F14 1 6 28 126 226 326 426 526 626 726 CMS Pixel C6F14 480 980 1440 1920 2400 2880 3360 3840 4320 4800 Silicon CMS C F 140 280 420 560 700 840 980 1120 1260 1400 Strips 6 14 Inner LHCb C F 7 40 73 106 139 223 306 389 472 556 Tracker 6 14 Trigger LHCb C F 4 25 47 68 89 142 195 248 301 353 Tracker 6 14 LHCb Rich 1&2 C6F14 1 3 6 9 12 19 26 33 39 48

The present investigation was necessary to understand the chemistry of the radiation induced processes, to evaluate the use limits of the fluids and the possibilities of their recovery (cleaning), as well. There are known the detrimental impurities for perfluorocarbon radiation hardness, namely H-and double bonds containing molecules, water and air. H and double bonds containing molecules can be removed using an adequate production technology by different producers and CERN requirements [6] established very low levels for these "evitable impurities". Water and oxygen are more or less inevitable due to manipulation, leaks, etc. Therefore, water and oxygen, as well as the eventual traces of greases have to be removed when the cooling plants are filled and on line when in use. PF 5060 (3M, USA) in the as received state was found not compliant, as H-containing molecules exceeded significantly the required limits. This fluid was however included in the irradiation program to check the influence of the relative high level of impurities on the radiation behavior and on the post-irradiation cleaning efficiency, as well. A specially purified fluid by a laboratory treatment of the as received PF 5060, which fulfilled the requirement of H-containing molecules, was also investigated for its radiation and cleaning behavior. The fluids tested in the present work are listed in Table 2.

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Table 2 - Perfluorocarbon fluids types studied within this work

No. Product name Supplier Composition

mainly iso-C F 1 Flutec PP1 F2 Chemicals Ltd., UK 6 14 (iso-perfluorohexane) mainly n-C F 2 PF 5060 DL 3M Chemicals, USA 6 14 (n-perfluorohexane) mainly n-C F 3 PF 5060 as received 3M Chemicals, USA 6 14 (n-perfluorohexane) 3M Chemicals, USA; tentatively " treated" mainly n-C F 4 PF 5060 "purified" (purified) in CERN Chemistry Lab. to meet 6 14 (n-perfluorohexane) the quality requirments cf. IT 3397/TS

2. EXPERIMENTAL

2.1 Experimental details

2.1.1 Irradiated perfluorocarbons The irradiation program included the fluid types in Table 2, as well as some specially impurified samples prepared in laboratory to simulate the possible real situations and to elucidate their role in the radiation induced damage. These impurities could be present in the fluids either as a result of technological fluctuations during their production (evitable impurities) or as possible accidental manipulation (inevitable impurities). The list of all the irradiated samples is shown in Table 3, together with their codes (acronyms) used in the report for each one.

2.1.2 Irradiation doses Two γ 60 Co integral irradiation doses were used: 28 kGy and 56 kGy. The irradiation doses were chosen in relation to the maxima of the expected integrated doses (Tab. 1).

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Table 3 - The perfluorocarbon fluids, doses and their respective codes Gamma 60Co dose Sample Report code (kGy) 0 PP1 Flutec PP1 28 PP1-28 56 PP1-56 28 PP1-EN-28 Flutec PP1 + 1-C F (1500 ppm) 6 12 56 PP1-EN-56 Flutec PP1 + air (4 bar) 28 PP1-A-28 28 PP1-AH-28 Flutec PP1 + air (1 bar) + H O (600 ppm) 2 56 PP1-AH-56 0 DL PF 5060 DL 28 DL-28 56 DL-56 0 PF 5060 PF 5060 as received 28 PF 5060-28 56 PF 5060-56 28 PF 5060-HE-28 PF 5060 as received + hexane (1500 ppm) 56 PF 5060-HE-56 PF 5060 as received + air (4 bar) 28 PF 5060-A-28 28 PF 5060-AH-28 PF 5060 as received + air (1 bar) + H O (600 ppm) 2 56 PF 5060-AH-56 0 purified PF 5060 laboratory purified PF 5060 28 purified PF 5060-28 56 purified PF 5060-56

2.1.3 Irradiation conditions The irradiations were realized at IRASM-IFIN-HH Bucharest (RO) with gammas 60Co [10] using a TOTE SVST-Co-60 box type irradiator (total activity: 150 kCi). The exposure times were 31.77 h and 63.53 h for the doses of 28 kGy and 56 kGy, respectively. To assure the uniformity of the irradiation dose, the fluid bottles were continuously moved during irradiation by the IRASM circulating containers system. A precise dosimetry was realized for the irradiated bottles using the dosimetric system ethanol–monochlorobenzene (ECB) with a PC controlled oscillometric readout. The perfluorocarbon fluids to be irradiated were prepared in the following conditions:

− C6F14 samples were transferred in stainless steel (ss) bottles built in CERN, (A type) of 0.7 L volume (Fig. 1); the bottles were conceived to resist at a service pressure of 3 bars, and were tested in CERN up to 8 bars [8]; − larger amounts of PP1 and PF 5060 were placed in cans (C type) of 5 L (Fig. 1); these recipients were the original ones used for delivery of PF 5060 fluid; they have a plastic internal liner (polyethylene) reinforced by an external metal envelop. The A type bottles were specially designed to allow both the pressure and atmosphere composition control as well as to make possible the corrosion and deposits studies. Thus, a valve and a flange were mounted on the superior part of the bottle. - 4 -

Inside of each bottle of type A, were placed aluminum strips (ISO Al 99.5 EN AW-1050 A, H-24) and stainless steel strips (316 L+N low carbon) to evidence the polymer deposits and the corrosion behavior. The dimensions of the aluminum strips were 180 ± 1 mm length, 9.6 ± 0.1 mm width and 0.8 ± 0.01 mm thickness; ss strips, had similar dimensions except the thickness (0.7 ± 0.01 mm). The strips were cleaned using the CERN procedure for high vacuum applications [9] and all were precisely weighted.

C

B

A

Fig. 1 - The bottles used for the perfluorocarbon fluids irradiation; the capital letters indicate the type of the bottle: A - for C6F14; B - for C3F8; C - large cans for C6F14 fluids irradiation.

2.1.4 Analysis methods UV-vis, FT-IR, F- ions determinations were made in the same conditions as described in the first part of the report [1]. The hydrogen fluoride (HF) content was evaluated by pH measurements using the following procedure:

− a sample of 20 - 30 g C6F14 is introduced in a polyethylene gas tight bottle (of 50 or 100 mL) and accurately weighted; the weight of C6F14 (w) sample is determined from the difference m - m0, where m is the weight of the bottle + sample, and m0 is the initial weight of the empty bottle; − 50 mL of demineralized water was introduced in a gas tight separation funnel (in HDPE) with a volume of 150 - 250 mL; after that is added the C6F14 sample; − the funnel content is shaken for 1 minute to extract HF from C6F14 in aqueous solution;

− after the separation of the two different phases (aqueous phase - up and C6F14 - down), the C6F14 phase is transferred in a glass bottle; the upper phase is passed in a 100 mL beaker and its pH is measured using a calibrated pH electrode (Metrohm 809 Titrando); − the HF content is then calculated using the formula (1):

-pH 6 CHF (ppm) = {[1000 (10 ⋅ 20)/ 50] / w}x10 (1) - 5 -

where: 10-pH is the H+ concentration; 20 is the molecular weight of HF; 50 is the volume of the 6 water phase (in mL); 1000 is the conversion factor mL to L; w = C6F14 weight; 10 is a conversion factor to ppm. GC-TCD analyses were carried out using a gas chromatograph Agilent 6850, with a 9 ft Porapak Q packed column, using an isotherm method (SORSEPT 06), under the following conditions: Inlet: 130 °C; injector: OFF; total flow: 19.1 mL/ min. He; column flow: 18 mL/ min.; oven: 130 °C; TCD heater: 180 °C; TCD reference flow: 30 mL/ min.; signal: 10 Hz; a loop of 0.25 mL was used to inject the gas samples; injections of 2.5 μL by a Hamilton syringe were used for the liquid (purified) samples1.

GC-MSD analyses of the irradiated C6F14 samples (gas phase and purified liquid) were made by an Agilent 6890 gas chromatograph using a Gas Pro capillary column, length 60 m, using an isotherm method (NOVEMBER 06), under the following conditions: oven: 140 °C; inlet: 140 °C; heater: 260 °C; MS source 230 °C; MS quad: 160 °C; gas saver: ON; split: 200 :1. A 0.25 mL loop was used to inject the gaseous sample; injections of 2.5 μL by a Hamilton syringe were used for the liquid (purified) samples. The pre-polymer content (high molecular weight molecules in the liquid phase) measurements A fluid sample of 15 - 30 g was weighted in a polyethylene gas tight bottle and passed in a 100 mL plastic beaker, previously weighted. The sample was kept at room temperature up to complete evaporation of the fluid (to facilitate the evaporation, the liquid was slightly flushed (ca. 50 mL/ min) by pure nitrogen. Then, the beaker was kept for 15 minutes at 45 °C, 15 minutes at room temperature and weighted again. The pre-polymer content was calculated according the following formula:

pre-polymer (%) = [(Mb+r - Mb)/w]x100 (2) where: Mb+r and Mb are respectively the weight of the beaker containing the non-evaporable residues and the weight of the empty beaker; w is the weight of the perfluorocarbon sample. The FT-IR spectra of the pre-polymer were recorded on a ZnS window (1 mm thickness). The residue obtained as described above, was dissolved in 10 mL of PP1 and 12 drops of this solution were placed on the ZnS window using a Pasteur glass pipette. The spectrum was recorded after the evaporation of the solution. If the concentration of the polymer was too small, other 12 drops were added and the spectrum was re-measured. Scanning Electron Microscopy (SEM) investigations were performed in TS-MME Metallurgy laboratory. The photos were produced with a Microscope Leo 430i, using EHT = 20 kV; the analyses were made using EHT = 10 kV and the microanalysis program Oxford ISIS.

1 To avoid corrosion phenomena in the GC columns, the measurements were made only on the gaseous phase of the irradiated fluids; the liquid phase was investigated after passing through adsorbent cleaners. - 6 -

2.2 Radiation induced effects

2.2.1 Generalities on the fluorocarbons radiolysis The primary radiolysis process consist in the formation of radicals, ions and excited molecules (time scale ~ 10 -16 s) The expected final radiation induced chemical effects on perfluorocarbon fluids, exemplified for n-C6F14, can be divided in three main categories, as shown in Scheme 1. It is generally accepted that the radiolysis of perfluorocarbons occurs mainly by radicals reactions and less by ions as intermediates. Possible reactions of F atoms and of perfluorcarbon radicals are presented in Scheme 2, respectively 3. F atoms recombine with other radicals, resulting a decrease of the final radiolysis yield; the formation of CF4, C2F6, etc. is due also to F reactions (F atoms have a faster mobility, hence a part of them can escape and do not recombine) [11]. For thermodynamic reasons, F2 molecules do not appear [11, 12]. Higher molecular weight products may result as it is described below for C9F20 isomers resulting from the radiolysis of n- C6F14 (Scheme 4). Low molecular weight products - homologous PFCs (C1-C5) - other fluorinated molecules if water and/or oxygen are present - fluoroalkenes, fluoroethers, fluoroalcohols

Acidity increase • • + - - C6F14 C6F13, F, C6F14*, C6F14 , e HF, F generating compounds (salts or hydrolysable fluorine compounds), and perfluoroacid formation

High molecular weight compounds - pre-polymers (soluble in C6F14); - polymers (which are insoluble)

Scheme 1 - General scheme for the perfluorcarbons radiolysis

scission of C-C bonds in excited molecules and recombination to result the initial molecule or to form low-molecular weight PFCs

* F3C F3C + CF2 cage + F

F3C CF4 + CF2

HF formation in the presence of Hydrogen sources

F + H HF +

Scheme 2 - Fluorine atoms reactions

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CF3 + CF3 C2F6

CF3 + C2F5 C3F8

CF3 + C3F7 C4F10

C2F5 + C3F7 C5F12

CF3 + C6F14 CF4 + C6F13 C F + C F C F + C F 2 5 6 14 2 6 6 13 Scheme 3 - Irradiated C6F14: possible radical reactions leading to low molecular weight products

Scheme 4 - Irradiated C6F14: possible radical reactions leading to high molecular weight products. (e.g. formation of perfluorononane isomers).

F- ions may appear when the irradiated perflurocarbon is in the presence of water or of a weak alkaline solution. These ions can be produced by HF dissociation or neutralization, by hydrolysis of some fluorine reactive compounds (e.g. carbonyl fluoride) or by extraction of some fluorine salts.

Water and oxygen can complicate the radiolysis mechanism. Even if H2O is a relatively simple molecule, in a radiation field it leads to many reactive species (Scheme 5) [13-17], which, by subsequent reactions increase the degradation of the fluorinated compounds [18]:

Water radiolysis

Event Time scale per s

H2O

+ - -16 H2O* H2O + e 10 H2O + -14 OH + H3O 10 -13 H + OH H2 + O 10

- eaq formation of molecular products in the spurs and diffusion of the radicals out of the spurs

- e , H, OH, H , H O , H O + -7 aq 2 2 2 3 10 Scheme 5 - Water radiolysis products [13-17] - 8 -

Oxygen is a radical scavenger, hence it leads to the formation of the carbonyl fluoride (CF2O) or to other fluorinated carbonyl compounds (perfluoroaldehydes or perfluoroketones) (Scheme 6).

C6F13 + O2 C6F13 OO

2C6F13OO 2+C6F13O O2 + C6F13O C5F11 CF2O C F O C F + CF CFO 6 13 4 9 3 Scheme 6 - Possible reactions involving the oxygen in perfluorocarbon radiolysis

2.2.2 Radiation induced acidity and the fluorine ions appearance The experimental data indicate a general acidity increase of the irradiated samples as compared to the unirradiated ones (see Table A 1.1 in Annex 1). This increase is accompanied by a similar increase of F- content. The lowest acidity (0.63 ppm HF) was observed for PP1-56. It was measured a higher acidity (21 ppm HF) in the case of less pure samples (e. g. PF 5060 - 56). DL-56 shown a value of 18 ppm HF and purified PF 5060 of 19 ppm HF. The high values of HF in DL-56 and purified PF-5060 can be attributed to air and water presence. Hexane, added as a hydrogen source does not influence significantly the HF content. In change, oxygen (air) presence induced the highest acid content. This effect could be explained by a high yield of COF2 which hydrolyzes during H2O extraction, leading to the formation of HF:

COF2 + H2O → 2 HF + CO2 (3)

The radioinduced appearance of COF2 was experimentally proven (see the section "Low molecular weight compounds" (2.2.4.). A moderate acidity increase was observed if water and oxygen (air) were together present. The fluorine ion content was 2-3 fold higher than the HF content in all the analyzed samples (Annex 1), excepting the initial (as received) ones, were the ratio was smaller. This effect can be explained by both the incomplete dissociation of HF in water solution and by the existence of soluble fluorine salts. A high amount of HF seems to be accumulated also in the gas phase, because of the low HF solubility in C6F14, as indicated by the metallic strips (see Fig. 4 and Annex 8); a blue discoloration of their upper part, in contact with the gaseous phase only, and a less corrosion of the strip immersed in liquid phase was observed in some cases (see Annex 8). The highest HF level was located in the bottle neck zone, due to the low density of the HF vapors as compared to the C6F14 ones.

2.2.3 High molecular weight molecules The concentration values of the high molecular weight molecules found in the liquid phase are listed in Annex 2 (Table A 2.1.). It was observed a proportional dependence of pre-polymers and polymers as a function of the irradiation dose for all fluids as shown in Fig. 2. The lowest amount of pre-polymer was observed in the as received PP1 samples (5.5 ⋅ 10-4 % in PP1-56). For a similar purity, DL shown a higher pre-polymer content (0.016 % - 9 -

in DL-56). Thus, the susceptibility to form pre-polymers could be related to the chemical structure: the branched structure of PP1 appears more resistant than the linear one of DL. The purity ratio is another competing factor which controls the formation of the pre- polymers. In the case of the linear C6F14 molecules series, the higher amount of pre-polymer was measured for the most impure ones (namely PF 5060-56; 0.314 %), the intermediary pure (laboratory purified PF 5060-56; 0.097 %) presents an intermediate pre-polymer content, while DL-56 (which is the most pure in this series) presents the lowest pre-polymer content (0.016 %). The fluid having a significant concentration of H-containing molecules resulted not only in increased acidity, but also in higher levels of the pre-polymer content (e.g. 0.372 % in PF 5060-HE-56). The presence of air (4 bars) reduced the pre-polymer content (see Annex 2, PP1-A-28 and PP1-28 or PF 5060-A-28 and PF 5060-28); this effect can be assigned to the oxygen molecules acting as a radical scavenger [19]. Similar effects - a reduced pre-polymer content – were observed also in the case of air and water containing samples (see Annex 2, samples PP1-28 and PP1-AH-28 or PF 5060-28 and PF 5060-AH-28 or PF 5060-56 and PF 5060-AH-56). However, in these cases, important white deposits on the aluminum strips and corrosion of stainless steel strips, as it is shown below, were evidenced. These effects suggest an important influence of water which resulted not only in an increased corrosion and formation of fluorine salts, but also in high amounts of polymer. The presence of a double bonds compound (in sample PP1-EN-28) resulted in a significant amount of pre-polymer (0.038 %), as compared to the free double bonds sample (PP1-28). This example illustrates clearly the detrimental effect of the double bonds containing molecules on the behavior of irradiated perfluorocarbons.

0.3

0.2 4

Pre-polymer (%) 0.1 3

2 0 1 0 10 20 30 40 50 60

Dose (kGy) Fig. 2 - Pre-polymer content as a function of the dose for the studied fluids: 1 - PP1; 2 - DL; 3 - purified PF 5060; 4 - PF 5060 as received. - 10 -

The FT-IR spectra analysis of the solid residues formed after evaporation of the pre- polymer solution leads to similar conclusions as the above mentioned gravimetric measurements. All the pre-polymers, separated by evaporation from the irradiated fluids, were transparent wax-like materials, soluble in perfluorohexane (linear or branched) or in hexane; their FT-IR spectra are presented in Annex 7. The pre-polymers absorbance band around 1100- 1230 cm-1 (Fig. 3) is similar to that observed in other perfluorinated compounds, such as, polytetrafluoroethylene [20], perfluorinated aldehydes [11], etc. A tentatively assignment of the observed bands is presented in Table 4. The structure of these pre-polymers can be considered to be similar to that of polytetrafluoroethylene with lower molecular weights. It is possible that some other groups, like H, double bonds, O to be present in these molecules, in low amounts. The pre-polymer was found to be relatively volatile; around 90 % of its initial weight is lost up to 150 °C (see Table A16.1 and Fig. A16.1 in Annex 16). Most of the UV optical absorption observed in the irradiated fluids is due to chromophore groups (C=O, C=C, etc.) grafted on the pre-polymer chain: an intense absorption was observed in the distillation residues of the irradiated fluids, accompanied by a significant decrease of the optical absorption of the distillation main fraction.

Table 4 - Tentatively assignment of the IR bands in the pre-polymers resulted at irradiation of the perfluorocarbons

In residue of irradiated PF 5060 Assignment Origin acid fluoride [21] oxygen influence -1 982 cm mixture of C-C vibration, CF3 and CF2 characteristic for perfluroethers stretching as well [22] architecture 1120-1280 CF2 stretching [23] perfluorocarbon polymerisation (perfluorocarbon radicals 1120...1230-1350 CF stretching [24-25] 3 recombination) 1342 C-C-H bend [24] 1380-1390 C-H bending [21, 24] H-containing radicals reactions 1460 C-H bending [21] 1700-1800 C=O stretching [20, 21] oxygen influence 1755-1735 -C=CF2 [20] radiation induced double bonds 1800-1780 -CF=CF2 [20] (polymer radiolysis?) acid fluoride groups attached to 1900-1870 oxygen influence fluorinated alkanes fragments [25] 2968-2860 C-H asym. stretching [20, 25] 2990 > CFH [25] H-containing radicals reactions 3008 - CF2H [25] 3062 CF3H [25]

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0.8 1231 0.6 1350 2940

0.4 1142 1390 2968

0.2 2880 1460 1720 Absorbance (abs. units) 982 2860

0 4000 3000 2000 1000 -1 Wavenumber (cm ) Fig. 3 - A typical FT-IR spectrum of the residue from PF 5060-HE-56

The presence of the polymers in the solid phase was measured by weighting the metal strips present in the irradiated fluids, partly immerged (see Annex 8). The visual inspection of the strips indicated in most cases (i.e. PP1, DL, purified PF 5060, PF 5060) the absence of a significant corrosion (or even no corrosion) and no visible deposits on the strip surface. No significant corrosion or deposits were observed in the fluids containing only oxygen, but very high deposits on the aluminum surface and a very intense corrosion of the stainless steel strips were evidenced for the fluids containing both air and water (Fig. 4). The observations and some illustrative pictures of the samples showing the corrosion effects or thick deposit layers are presented in the Annex 9. Fig. 5 shows an example (of aluminum strip from PP1-AH-60) which illustrates the quite important thickness of the deposit (polymer layer), especially in the gaseous phase. It was evidenced a thicker deposit layer in the gas phase than in the liquid for all samples irradiated in the presence of both air and water. An explanation could be that the observed deposits are mainly fluoride salts resulted by gaseous HF attack. Polymerization could occur also in the gas phase due to the influence of some water • • radiolysis products (such as HO , H , H2O2) which act in the radical polymerization reactions as initiators. liquid

liquid gas

(a) gas (b)

Fig. 4 - Aspects of the metal strips irradiated in perfluorocarbon fluids: (a) Inox from PF 5060-AH-56; (b) aluminum strips (from left to right): PF 5060-AH-56, DL, and initial (reference). - 12 -

gas phase liquid phase

1 mm

Fig. 5 - The liquid-gas interface for an aluminum strip present in PP1-AH-56

The SEM micrographs indicated clearly the existence of different deposits in all cases. The amounts varied, depending on the fluid nature and the type of impurities. Some observations are listed below; the comparative pictures are shown in Annex 10: 1. On the reference stainless steel (ss) samples SEM micrographs it can be clearly seen a sharp separation between the metal crystallites; the (ss) strips immersed in irradiated C6F14 exhibit a less sharp separation between the crystallites, and a less brightness (see as an example Fig. 6); the mentioned characteristics become more intense when the fluid was less pure or the dose was increased; the results are in good agreement with the pre-polymer measurements (in liquid phase, see Annex 2) and with the mass of deposits evaluations (Annex 8); thus, the deposits appear significantly more abundant in PF 5060-HE-28 and PF 5060-HE-56 than in PP1-56; the observed changes can be related both to polymer deposits on the surface and to HF corrosion of the metal. 2. The sample PF 5060-HE-56 exhibits some white islands which could be either radiation induced polymers or fluorinated salts. These deposits, composed by round particles, were not visible in the case of PP1 as received fluid irradiated at the same dose. 3. The aluminum strip immersed in PF 5060-HE-28 exhibits uniform deposits composed by pin-shaped particles. At 56 kGy (PF 5060-HE-56), both pin-shaped composed deposits and islands composed by rounded particles (similar to those observed on ss) are observed. No deposits - or no significant deposits - were observed on the surface of the samples immersed in PP1 and irradiated at 56 kGy (PP1-56). Similar deposits were observed in previous tests performed on less pure fluids [26 - 29]. 4. Fluorine and carbon elements were identified in the deposits (see the Table A10.1 in Annex 10). The highest fluorine content was observed in the case of hexane containing PF 5060 (i.e. PF 5060-HE-28 and PF 5060-HE-56 samples), both in the region of the gas phase contact and in the liquid one. The fluorine content can be partly related to fluorides formation. Polymers also should result in significant amounts; in Fig. 7 is shown a micrograph which illustrates the formation of the polymer on the strips surface (typical filaments specific for fluorinated polymers can be clearly observed). 5. In the case of pure PP1, the radioinduced polymer quantity is very small, as indicated the gravimetric and the FT-IR results on the residue, the SEM observations (slight differences as compared to the reference, comparable amounts of C and F) as well as the gravimetric determinations on strips. - 13 -

6. Oxygen (air) presence leads to a very high acidity, as it was shown above, due to carbonyl fluoride formation and its subsequent hydrolysis (in the presence of the humidity); the corrosion was moderate. 7. When both air and water were present, various high deposits and an intense corrosion were observed for the two fluid types: PF 5060 and PP1. The surface of ss strips appeared heterogeneously covered by various deposits both for PP1-AH-28 and PP1-AH-56 and also for their PF 5060 counterparts (PF 5060-AH-28, PF 5060- AH-56). (see Fig. 8 a, c and Fig. 9 a, c as well as Annex 9 and 10). On the aluminum strips, it appears to be at least two more superposed layers, as it can be clearly seen in Fig. 8 b and d and 9 b and d. The white upper deposit is probably a fluorinated polymer, while the second (which is in the shape of a broken coat) could be a fluorine salt or oxide. The non-immersed parts of the aluminum strips were covered by abundant white deposits (ca. 2-3 mm); they could be mainly fluorine salts resulted from HF corrosion process. XPS analysis revealed radiation induced changes in the ratio Fe/ Cr in stainless steel strips. Thus, most of Cr disappeared on the strip surface, this resulting in increased corrosion susceptibility of the steel. The process is accompanied by completely disappearance of P and Si as well as by increase in fluorine content.

(a) (b)

(c) (a)

Fig. 6 - SEM images of some ss strips: (a) reference (strip no. 13 ss); (b) PP1-56 (strip no. 32 ss); (c) PF 5060-HE-28 (strip no. 36 ss); (d) PF-5060-HE-56 (strip no. 30 ss).

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Fig. 7 - Polymer layer evidenced on a scratched ss strip

(a) (b)

(c) (d)

Fig. 8 - Deposits on the metallic strips immersed in C6F14 fluids impurified with water and air: (a) - stainless steel PF 5060-AH-56 (strip no. 43); (b) - stainless steel PP1-AH-56 (strip no. 26);(c) - aluminum PF 5060-AH- 56 (strip no. 26); (d) - aluminum PP1-AH-56 (strip no. 34).

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(a) (b)

(c) (d)

Fig. 9 - Deposits on the metallic strips immersed in PP1-AH-28: (a, c) - stainless steel (strip no. 33); (b, d) - aluminum (strip no. 30).

2.2.4 Low molecular weight products (LMwPs) Radiation induced scission processes result in low molecular weight (i.e. molecular weight lower than the perfluorohexane) products. They are found in both liquid (solved in perfluorohexane) and in gaseous state, resulting in a pressure increase (Annex 1). The existence of the LMwPs has been also evidenced by chromatography (GC-MSD and GC-TCD, see Annex 3-6) as well as by FT-IR spectroscopy (see Annex 15). Generally, the low molecular weight perfluorocarbons and the functionalized fluorocarbons (H-, O- or double bonds containing), are expected to be found in the irradiated fluids, both in their gas phase and in liquid phase. GC (MSD and TCD), FT-IR spectroscopy and UV-Vis spectrophotometry were applied to evidence the LMwPs in the irradiated fluids. Note that the GC analysis of the liquid phase was realized on previously purified liquids to protect the chromatograph columns against corrosion. a) PP1 fluid - The results concerning the GC-MSD analysis of the PP1 fluid irradiated samples are presented in the Annex 3. The chromatograms in gaseous phase of irradiated PP1 (see Fig. 10 and Annex 3) revealed the presence of the low molecular weight perfluorocarbons (C1 - C5) resulted by radiation induced fragmentation of the initial iso-C6F14 molecules. Some of these molecules existed also in the initial fluid, but in smaller amounts. A higher concentration was observed for both CF4 and C5F12. All other peaks of the LMwPs perfluorocarbons are also increased, but no significant amounts of other molecules were observed. - 16 -

Among the very small peaks, there are three attributable to possible traces of (CF3)3CF and CF3- CF=CF-CF3 and (CF3)2C=CF2, respectively. The last one, called perfluoroisobutene (Annex 11) is one of the most toxic substance (10 folds toxic than the phosgene) [30]. However, it is easily decomposed in the presence of water (humidity) [31], as well as in the presence of the usual electrophilic reactants. The purification cartridges, based on alumina and molecular sieves can decompose the perfluoroisobutene efficiently [32]. As a safety caution (see Annex 11), when the installation is opened after long use period, it is recommended to ensure a good ventilation - exhaust of the working space; the operators should use the respiratory protection equipment (respiratory protection with either air bottles or with filtering cartridge); protective glows for the skin and safety spectacles are also recommended. The number of the radiation induced low molecular weight molecules and their concentration is lowest in the case of PP1 as compared to other studied C6F14 fluids, as it can be seen in Fig. 11.

Fig. 10 - Details of the chromatograms (GC-MSD) of PP1 fluid initial and after irradiation (gas phase analysis): focus on the initial portion, up to the main peak of iso-C6F14 (not shown).

- 17 -

Fig. 11 - Comparative GC-MSD chromatograms of the irradiated C6F14 fluids: NOV13 = PP1-56; NOV34 = PF 5060-56; NOV41 = purified PF 5060-56; NOV50 = DL-56.

In the case of PP1-28 sample, which was irradiated in a no gas tight can, as well as for the impurified samples (PP1-A-28, PP1-AH-28 and PP1-AH-56), higher amounts of C5F12 were observed, suggesting an increased chain scission in the presence of air or of air/water mixture. In the case of PP1-28, the radiation induced cracks in the can's polyethylene liner; air and humidity diffused slowly in the can and influenced significantly the radiolysis (see Annex 3, Tab. A 3.1. and A 3.2.). Polyethylene radicals could also recombine with the perfluorinated ones leading to H-containing molecules traces (observed mainly for the products with a higher molecular weight than C6F14). No LMwPs - (CF4, C2F6, etc.) - were detected in this case, due to their volatility.

COF2 was found in important amounts in the case of PP1-A-28 by both GC-MSD (Annex 3, 5) and by FT-IR spectroscopy (Fig. 12). The bands observed at 1936, 1908, and 1890 -1 cm (Fig. 12) are characteristic to C=O vibration modes in carbonyl fluoride (COF2) and in related compounds (R-COF; R = CH3...) [22]; the presence of carbonyl fluorides in PP1-A-28 is thus possible. COF2 was also detected by GC-TCD technique, by measuring the CO2 content before and after water treatment (Figs. 13, 14); COF2 is decomposed according to the above mentioned reaction (3). Several other small peaks attributable to oxygen containing molecules (fluorinated acids, esters, anhydrides) were found both by GC-MSD and FT-IR in PP1-A-28. The high level of CO2 found by GC-MSD was related to the COF2 decomposition.

A relative high level of CO2 was detected also in the case of PP1-28 by GC-MSD; it can be assigned to COF2 formation in presence of oxygen molecules and to its subsequent decomposition in presence of the humidity. FTIR spectra confirm this assumption, the intense -1 -1 -1 -1 bands of CO2 (at 2338 cm and 2363 cm ) and two bands at 1889 cm 1876 cm , indicating - 18 -

the existence of homologous carbonyl fluorides (RCFO; R = CF3 or higher) [22]; these bands disappeared after purification (see Annex 15).

0.12 1890

0.08 1 1908 1875 1936

0.04 1798 1783 Absorbance (a.u.) 1820 2 0 3 4

2000 1900 1800 1700

-1 Wavenumber (cm )

Fig. 12 - Evidence of COF2 presence in liquid PP1 by FT-IR: 1 - PP1-A-28; 2 - PP1-A-28 after water extraction; 3 - PP1-56 (inert atmosphere); 4 - Reference unirradiated PP1. The bands at 1936 and 1908 cm-1 and -1 -1 1890 cm are characteristic for CF2O [22]. Other absorption bands (such as 1870 cm ) correspond to various RCFO compounds or to perfluoro-acids and perfluoro-aldehydes which are also eliminated (partially or totally) by water treatment.

Various H-containing molecules, such as CHF3, CF2HCF3, 1-HC6F13, etc., (see Table A 3.1. in Annex 3) were detected in the case of PP1-AH-28 and PP1-AH-56 samples, indicating a clearly interference of water radiolysis products (see Scheme 5) in the perfluorohexane radiolysis mechanism. Oxygen and hydrogen containing fluorinated molecules were also detected in these cases. No CF2O was detected in air and water containing perfluorocarbons, due to its possible hydrolysis, but important amounts of CO2 suggest the formation and the subsequent decomposition of this compound (see Annex 3, 5 for GC-MSD data in gas phase, and Annex 15 for the FT-IR spectra). Moreover, among the oxygen containing molecules, important amounts of RCFO were detected by FT-IR (see Annex 15, the bands at 1888 cm-1 and 1873 cm-1). Traces of fluorinated alkenes (1801 cm-1 1773 cm-1) or C=O containing compounds (1733 cm-1 and 1716 cm-1) were also identified (see Annex 3, 5 and 14).

It should be noticed that COF2 (carbonyl fluoride) is a toxic and corrosive gas. It decomposes in the presence of the water [see the reaction (3), in Ch. 2.2] and forms HF (see its security sheet and some other data in the Annex 12). The proposed purification systems, based on adsorption cartridges (especially alumina and molecular sieves components) are able to decompose quantitatively the COF2 which could result accidentally if air or oxygen will are present in the fluid [32] (Annex 14).

- 19 -

Fig. 13 - Evidencing the COF2 presence in gaseous phase of the PP1-A-28 by GC-TCD analysis: CO2 concentration changes after the water treatment of the gas phase.

Fig. 14 - Evidencing the COF2 presence in liquid phase of the PP1 + air/ 28 kGy by GC-TCD analysis: change in CO2 content after the water treatment of the liquid phase (COF2 hydrolysis).

When pure PP1 (previously flushed by Ar and pumped) was irradiated (PP1-56) in a gas tight bottle, no supplementary peaks were observed in the liquid phase, excepting those of the lower molecular weight homologous to 2-methyl-perfluoropentane and of other similar perfluorocarbons (Fig. 15). The most important low molecular weight component found is C5F12, which also exists in the PP1 in a similar amount (Table A 3.2., in Annex 3).

- 20 -

Fig. 15 - Focus on the first parts of the chromatograms (GC-MSD) in liquid phase of PP1 fluid initial (Nov53.D) and after irradiation at 56 kGy and purification (Nov21.D); the main peak of iso-C6F14 is not shown.

b) Irradiated DL fluid samples had a similar behavior as the PP1 ones, i.e. an increase of the low molecular weight perfluoroalkanes content and no significant amounts of other molecules (see Annex 2, 4 and 8). CF4, C2F6 and C4F10 resulted as most important amounts; relative high levels of C3F8 and C5F12 were also identified in the irradiated fluid. These components are found in similar concentrations in both PF 5060 (as received) and purified PF 5060, hence they and can be considered as specific for the radiolysis of these fluids. The types and the concentration of low molecular weight products identified in the irradiated DL were higher than in the case of PP1, but lower than in the case of purified PF 5060 and PF 5060 as received (see Fig. 11 and Annexes 3 - 6). A slight increasing in CO2 concentration in the gas phase of the irradiated samples suggests the existence of COF2 traces of other reactive fluorinated molecules which can decompose in contact with the air. A wide but weak absorption was observed in the region of 3100 cm-1; this absorption was typically observed in all the irradiated samples. Because the intensity of this band increased when the oxygen (air) content was higher, it was assigned to the products of the reaction of perfluorocarbon radicals with oxygen traces. Note that in the FT-IR spectra region 2500 - 1400 cm-1 of the irradiated DL, there are many small peaks (see Annex 15). The peaks located at 1880 cm-1, 1824 cm-1 and 1781 cm-1 (carbonyl compounds and alkenes) disappeared after the purification treatment, but other remained; they could correspond to the small peaks detected by GC-MSD and can be traces of various O-substituted fluorinated molecules and fluorinated alkenes. c) PF 5060 - GC-MSD chromatograms of the gaseous phase of irradiated PF 5060, (see Annex 5) shown many peaks attributable to various LMwPs (see Table A 5.1 - A 5.2. in the Annex 5), formed as a result of the interference of the various impurities present in the as received fluid. The observed radiation induced LMwPs (see Table A 5.1) can be divided in several categories:

− low molecular weight pefluorinated molecules (CF4, C2F6...); − unsaturated molecules, low molecular weight (C3, C4 perfluoroalkens, H containing − fluorinated alkenes, e.g. CF=CH-CF3; - 21 -

− H containing molecules, with low or high molecular weight (e.g. CF3H, C2F5H, 1- HC6F13, 2-HC6F13 a.s.o., including also the molecules containing more than one H atom); − O containing molecules (ethers, carboxylic acids, carbonyl compounds);

− CO2, COF2, R-COF2; the peaks of these products were sometimes masked by the neighboring ones (i.e. C2F6) in the case of PF 5060-HE-56.

Among the identified perfluoralkenes, CF3CF=CF2 was observed in an important amount (ca. 0.050 %) in PF 5060-56. Perfloroisobutylene was also detected in relative low concentration. The concentration of LMwPs increases with the irradiation dose. FT-IR spectra of the irradiated PF 5060 confirm the results of GC-MSD and GC-TCD. (see Annex 15). The types and the intensity of the bands attributable to radiation induced LMwPs increase with the irradiation dose and as a function of the initial impurification. Thus, air + water or only air induced many small peaks, similar tot those observed in the case of PP1. The peaks structure is complicated by the interference of H atoms from hexane. CF2O and other reactive carbonyl fluorides were evidenced by both FT-IR and GC-MSD, especially when air (oxygen) was present during irradiation. Most of the radiation induced LMwPs were removed by purification treatment, as indicated the GC-MSD chromatograms and FT-IR spectra (see Annex 3-5 and 15). The influence of the impurities present in the as received PF 5060 fluid, as well as the linear structure of the C6F14 molecule, result in a different spectrum of PF 5060-A-28 as compared to that of PP1-A-28 (Fig. 12) in the region 2000 - 1500 cm-1. Thus, the lack of the absorption band at 1938 cm-1 and the weak intensity of that located at 1891 cm-1 in PF 5060-A- 28 are the remarkable differences relative to PP1-A-28; they suggest that CF2O does not result preferentially in irradiated PF 5060, but also with other R-CFO molecules; the peak at 1782 cm-1 existing in PF 5060-A-28 suggest an increased tendency of this fluid to form C=C unsaturated molecules. d) Purified PF 5060. In the gas phase of purified PF 5060-28 and of purified PF 5060-56 were observed the peaks of the low molecular weight perfluorcarbons (C1-C6) and several others which can be assigned to various other LMwPs (the importance of these products is reduced, their total area did not exceed 0.1 %). Thus, irradiation resulted especially in formation of CF4, C2F6 and C3F8. The amount of these compounds increased with the dose. Traces of H-compounds resulted also, probably by an interference of water traces with perfluorohexane radiolysis. Same peaks as in the case of both irradiated PF 5060 and DL were also observed in FT- IR spectra of the irradiated purified PF 5060. Radiation induced effects, as they are observed in the FT-IR spectra are rather low, but most of the impurities peaks were not removed by the purification treatment, similar to other PF 5060 fluids; this behavior suggest that most of the impurities are fixed on large perfluorinated molecules which can escape to adsorption interactions. FT-IR results are in concordance with the UV data which indicate no changes in the absorbance before and after adsorption treatment of the irradiated purified PF 5060 (see ch. 2.3.2. and Annex 14).

The pressure measurements (see Annex 1) shown that the amount of LMwPs is higher in the case of less pure fluid (PF 5060 as received) and lower in the case of the pure ones. For similar purities, the radiation induced increase of the pressure was higher in the case of DL than in the case of PP1, indicating a higher amount of LMwPs in DL. GC-MSD and FT-IR spectra had shown also higher amounts and more types of LMwPs in the case of irradiated DL than in the case of irradiated PP1. These results suggest higher radiation hardness of the branched perfluorohexane (PP1) as compared to linear (DL); this conclusion is in concordance with - 22 -

previous literature data, which indicate lower radiolysis yields for iso-C6F14 as compared to n- C6F14 [33]. A possible explanation of this increased hardness is that CF3 branched groups can induce another radiolysis pathway based on CF4 formation [22]. The higher amount of CF4 found in the gas phase of irradiated PP1 as compared to irradiated DL support this hypothesis and is in concordance with literature data concerning the CF4 radiochemical yields [33]. Other authors concluded that the F atom removal from the terminal CF3 groups is more difficult than from CF2 ones; this can explain the increased CF4 amount measured in the gas phase of irradiated PP1 (iso-C6F14) as compared to irradiated DL, as well as the higher radiation hardness of the iso- C6F14 [33].

2.2.5 Correlation between the literature and the experimental data; qualitative and quantitative radiolytical effects

The radiochemical yields (G-C6F14) for radiation induced destruction of iso-C6F14 and n- C6F14 from literature are 2.71 and 2.88, respectively [33], namely 2.71 molecules of iso-C6F14 or 2.88 molecules of n-C6F14 are destroyed for each 100 eV of radiation absorbed energy.

Expressed as a mass percentage, the radiation induced destruction for the pure iso-C6F14 (PP1) or for the pure n-C6F14 (DL), using the literature G-C6F14 values, can be calculated as follows: − dose transformation: 28 kGy = 28000 J/kg. (1kGy = 1kJ/kg) − absorbed energy (E): for the irradiated weight of 900 g (2.663 mol), the absorbed energy is 28000x0.9 = 25200 J, i.e. 1.58x1023 eV. (1 eV = 1.6x10-19 J); − number of the destroyed molecules: G x E (eV)/100: 21 -2 • for iso-C6F14: 4.28x10 molecules (0.71x10 mol); 21 -2 • or DL, will be 4.55x10 molecules (0.76x10 mol);

− the final destruction ratios: (nmol of destroyed C6F14/nmol of C6F14 initial)x100 are: • for iso-C6F14: 0.27 % (dose = 28 kGy) and 0.54 % (dose = 56 kGy); • for n-C6F14: 0.29 % (dose = 28 kGy) and 0.58 % (dose = 56 kGy); The correlation between the literature data and the experimental values of the destruction ratio was realized using the chemical analyses results obtained within the present work. It was taken into account the main radiolysis products, namely LMwPs, the high molecular weight products (pre-polymers) and polymers, as well as the results concerning both the radiolytical products in the gas and liquid phase. As an example, it is presented below the evaluation for PP1-56 fluid (803 g; 99.32 % purity, i.e. 797.54 g iso-C6F14, or 2.3596 mol).

The mass of the gas atmosphere was evaluated assuming that 90 % is C6F14. The mass of the gas (vapors) atmosphere was calculated using the molar volume of the C6F14 (vapors), i.e. 81 L/ mol at 0.3 atm and room temperature [34]; thus, 1 L of gas contains 0.0123 mol C6F14. The volume of the vapors atmosphere was 227 mL for PP1-56 sample; the number of mol will be 6.15x10-3 and the corresponding mass is 0.944 g. The amounts of various components both in gaseous phase and liquid phase were calculated based on GC-MSD, potentiometric and gravimetric analyses, as shown in Table 5 below. The as received fluids contained small amounts of C5F12, C7F16, etc.: the difference only was taken into account for the irradiation process.

- 23 -

Table 5 - Experimental evaluation of various radioinduced products in PP1-56 (dose: 56kGy; fluid mass = 803 g)

Components identified in the gas phase Peak Δ radiation induced Component Method mass (g) mol 10-4 (%) (mol 10-4) CO2 - - - - -

CF4 3.24 GC-MSD 0.060 3.45 3.45 C2F6 1.024 " 0.0095 0.68 0.68 C3F8 0.661 " 0.0062 0.33 0.33 C4F10 0.286 " 0.0027 0.11 0.11 cyclo-C5F10 0.007 " 0.00006 0.028 0 -4 CF3CF=CFCF3 0.002 " 0.19x10 negligible negligible -4 (CF3)2C=CF2 0.001 " 0.09x10 negligible negligible C5F12 1.024 " 0.0096 0.34 0.11 iso-C6F14 93.55 " 0.8853 26.14 - 1.78 n-C6F14 0.089 " 0.0008 0.025 0.01 n-C7F16 0.011 " 0.0001 0.0023 ∼0 PFC + O 0.022 " 0.0002 0.06 0.06 Total mol of radiolysis products appeared in gas phase 4.75 (all are PFCs)

Components identified in the liquid phase Δ radiation induced Component (%) Method weight (g) mol 10-4 (mol 10-4) C3F8 0.004 " 0.032 1.7 1.7 C4F10 0.016 " 0.128 5.4 5.4 cyclo-C5F10 0.002 " 0.0161 0.5 0 C5F12 0.271 " 2.18 75.6 0 cyclo-C6F12 0.009 " 0.0723 2.2 1.96 iso-C6F14 98.90 " 794.2 23496 - 100 n-C6F14 0.314 " 2.52 64.95 13.64 C7F16 0.113 " 0.907 23.39 14.08 other molecules 0.345 " 2.77 82 38.8 (r.t. < 30 min) pre-polymer 0.007 gravimetric 0.35 10.4 10.4 polymer n.a. - - 0 0 HF 6.3x10-5 potentiometric 0.0005 0.25 0.25 F- 2.0x10-4 " 0.0016 0.84 0.84 Total mol of radiolysis products in the liquid phase 87.07 Total mol of radiolysis products 91.82

The degradation ratio is expressed as numbers of mol of the radiolytical induced products or as C6F14 number of mol consumed in the radiolytical process. The destruction ratio related to the radiolysis products is:

(nmol radiolysis products/nmol iso-C6F14 initial)x100 = (91.82/23622)x100 = 0.39 %

The destruction ratio related to the C6F14 mol is:

(nmol C6F14 transformed in various products) /(nmol iso- C6F14initial) = 101.78/23622)x100 = 0.43 %

The average value is 0.41 %, close to the value found (0.54%) using the literature value of G-isoC6F14. - 24 -

Similar evaluation in the case of DL-56 (899 g fluid, 98.59 % purity, i.e. 886.32 g n- C6F14 or 2.6222 mol) leads to an average value of 0.66 % for DL-56, close to the value found (0.58%) using the literature value of G-n-C6F14, confirming the higher radiation sensitivity of the DL fluid.

The corresponding experimental radiochemical yield (G-C6F14) values are 2.18 for PP-1 and 3.30 for DL. All these values are close to those from the literature data [33]. Apart the influence of the molecular structure, the different impurities determines the modification of the radiation susceptibility of the irradiated fluids; hence, higher radiochemical yields should be expected in such fluids as compared to the pure ones. The overviews of the radiation induced effects on the four C6F14 main types of perfluorocarbon fluids used in this work are presented in Figs. 16-23. The influence of the purity state of the fluids is clearly evidenced.

25 PF 5060-28 70 PF 5060-28

20 purified 60 purifed PF 5060-28 50 PF 5060-28 15 40 DL-28 DL-28 10 30

- 20 F contentF (ppm) HF content(ppm) 5 PP1-28 10 PP1-28 0 0 Fig. 16 - HF equivalent content induced in Fig. 17 - F- content induced in the fluids by the fluids by. irradiation at 28 kGy.. irradiation at 28 kGy

0.16 4.0 PF 5060-28 0.14 3.5 PF 5060-28 purified 3.0 0.12 purified PF 5060-28 0.10 2.5 PF 5060-28 2.0 0.08 DL-28

0.06 (abs.units) 1.5 0.04 1.0 DL-28 0.02 UV absorptionnm at 190 0.5

Pre-polymer content (%) PP1-28 PP1-28 0.00 0.0 Fig. 18 - Polymer content induced in the Fig. 19 - UV absorption induced in the fluids fluids by irradiation at 28 kGy. by irradiation at 28 kGy.

25 100 PF 5060-56 purified PF 5060-56 PF 5060-56 20 DL-56 80 purified 15 60 PF 5060-56 DL-56 10 40 - F content (ppm) F content

HF content (ppm) 5 20 PP1-56 PP1-56 0 0 - Fig. 20 - HF equivalent content induced in Fig. 21 - F content induced in the fluids by the fluids by irradiation at 56 kGy. irradiation at 56 kGy. - 25 -

0.35 purified PF 5060-56 3.0 PF 5060-56 0.30 PF 5060-56 2.5 0.25 2.0 0.20 1.5 0.15 purified PF 5060-56 units) (abs. 0.10 1.0 DL-56 Pre-polymer content (%) content Pre-polymer

UV absorption at 190 nm 190 at UV absorption 0.5 0.05 DL-56 PP1-56 PP1-56 0.00 0.0 Fig. 22 - Polymer content induced in the Fig. 23 - UV absorption induced in the fluids fluids by irradiation at 56 kGy. by irradiation at 56 kGy.

2.3 Purification of perfluorocarbon fluids There are two directions related to the purification of the perflurocarbon fluids, namely: − purification of the as received fluids in order to remove the detrimental impurities eventually present and to render them compliant to the CERN requirements; − purification (cleaning) of the irradiated fluids to remove the radiation-induced detrimental molecules - acid (HF), polymer (or products with higher molecular weight than the base molecules), other molecules (e.g. fluorinated carbonyl compounds, alkenes, H-containing molecules, etc.).

2.3.1 Purification of the as received fluids The chemical analysis already performed [1] shown that PP1 and DL fluids meet the CERN requirements and is not necessary a supplementary purification, excepting an inert gas flushing (or pumping) to remove the air traces and a drying on alumina or molecular sieves to remove the water traces (which can appear following the liquids manipulation, cooling system charging, etc.). The PF 5060 (as received) fluid, did not meet the CERN requirements mainly due to its high content in H-containing molecules. Our experiments presented in Annex 13 show that a treatment using activated carbon (and with other adsorbents) can efficiently remove the detrimental impurities (especially H- containing molecules), as it can be seen from data in Tables A 5.2 and Table A 6.2., in Annex 5 and 6 respectively. Thus, the composition of the purified PF 5060 became similar to that of DL. The main difference consists in the persistence of the trace amounts of some high molecular weight components (especially those with r.t. > 20 minutes). The as received and purified PF 5060 was also included within the irradiation program. Its behavior was close to that of DL: similar values of pressure after irradiation, radioinduced acidity and F- ions content were measured (see Annex 1). The content of pre-polymer is about 3- 5 folds lower than in as received PF 5060, but higher than in DL (see Annex 2). The amount of solid deposits is lower than in the case of as received PF 5060, however higher as compared to DL. The metallic strips did not show visible corrosion traces (see Annex 8) and no white abundant polymer deposits were observed (see Annex 10). These experiments proven the possibility to enlarge the area of usable fluids in CERN by applying adequate treatments on the available, less pure ones. - 26 -

2.3.2 Purification (cleaning) of the irradiated fluids types The aim of the cleaning process was to remove the radiation induced undesirable molecules which affect the fluid initial properties by increased corrosion potential (due to HF, COF2, fluorinated acids a.s.o.), polymerization potential (due to fluorinated alkenes), increased viscosity and formation of deposits (due to high molecular weight molecules), toxicity (due to perfluoroisobutylene and COF2). Other radioinduced impurities, namely the low molecular weight homologues of the C6F14 or others (e.g. cyclo-perfluoroalkanes) can be considered as non-detrimental taking into account their similar structure, properties and behavior in a radiation field. The selective adsorption, using appropriate materials can be easily adapted to an on-line circulating system. The cleaning experiments realized within the present work on irradiated fluids included both static and continuous adsorption tests, as well as distillation tests. UV-vis spectro- photometry, FT-IR spectroscopy and gas chromatography (both GC-TCD and GC-MSD) were used as main methods for the investigation of the quality of the purified fluids. All the results proven that the adsorption purification of the fluids is efficient: activated carbon, alumina, and molecular sieves were effective for this purpose. UV-vis absorption was used as a rapid method to assess the fluids quality. All the irradiated fluids presented high values of UV optical absorption which decreased as a function of both the fluid type and the cleaner types and effectiveness (Annex 14). Due to the complex composition of the irradiated fluids, the utilization of a multiple adsorptive layers appeared as necessary. Activated carbon is efficient to remove the fluorinated molecules containing H and O atoms but less efficiently removed the fluorinated alkenes [1]. Alumina and molecular sieves are effective for water and CO2 removal, as well as the above mentioned H- and O-containing molecules. Due to their low basicity, alumina and molecular sieves are also effective to remove the COF2, perfluoroisobutylene, HF and fluorinated acids. In the case of PP1 irradiated fluid (PP1-28 and PP1-60), were observed the lowest UV (190 nm region) absorbance values among all the samples (see Fig. 16 and Annex 14). UV absorbance decreased quickly when the cleaning treatment was applied (see Fig. 17 and Annex 14). It is to be noticed that the UV absorbance of the PP1 irradiated in gas tight conditions (PP1- 56) was lower than in the case of the liquid irradiated in the can (no gas tight because the radiation induced cracks in polyethylene bottle and air and humidity were present).

3

4 2

3 1 2

Absorbance (abs. units) Fig. 24 - UV-Vis spectra of the irradiated fluids (references initial, unirradiated fluids): 1 - PP1-28; 2 - DL-28; 3 - purified 1 0 PF 5060-28; 4 – PF 5060-2828 kGy 200 250 300 350 Wavelength (nm)

- 27 -

The purification systems were efficient for the irradiated PP1 fluid, and its UV absorbance was reached the initial values, in the case of PP1-28, PP1-56 and PP1-A-28. GC-MSD, GC-TCD and FT-IR spectra confirmed that the purity of the treated fluids is close to that of the as received, pure, one. The main differences consist in trace concentration of low molecular weight perfluorcarbons and traces of high molecular weight products (with r.t.> 20 minutes). When air and water were present (PP1-AH-28 and PP1-AH-56), a residual UV absorbance was observed, even when further treatments were applied. GC-MSD chromatograms proven that the treated fluids are close to the as received one; small peaks in FT-IR spectrum suggest the possibility of the existence of traces of C-O-C, C=O and C=C groups grafted on large fluorocarbon molecules. Such groups can be responsible for the observed UV optical absorption. Irradiated DL (DL-28 and DL-56) presented the lowest UV optical absorption as compared to other n-C6F14 containing fluids (PF 5060 and purified PF 5060). However, the purification of DL irradiated fluids cannot remove the traces responsible for the UV optical absorption; even it tends to increase slightly after some treatments. However, the GC-MSD and FT-IR data indicate that the fluid composition is similar to the as received one. The most important difference consists in some small peaks at r.t > 20 minutes in the GC-MSD chromatogram of the irradiated fluid. These peaks can be related to the presence of high molecular weight fluorinated molecules (pre-polymers) containing C=C bonds (which are known to absorb strongly in UV). FT-IR spectra of the purified DL irradiated fluids present some small absorption peaks in the region of 1700 - 1800 cm-1 which can be also related to traces of the mentioned molecules. In the case of PF 5060 irradiated fluid, the residual UV optical absorption was considerably higher. It did not steadily decreased when fresh adsorbent material was used (Fig. 17), but decreased significantly after distillation. However, GC-MSD chromatogram and FT-IR spectrum of the purified irradiated fluid were similar to those of the as received fluid. Hence, it can be considered again that the UV absorbance is due to the traces of high molecular weight molecules (no pre-polymer was detected in the purified liquid). Distillation reduced significantly the UV absorbance of PF 5060-28 as well as of other PF 5060 irradiated samples. When the purification treatment was applied on the main fraction obtained after distillation (see Annex 14), the UV optical absorbance of PF 5060-28 completely disappeared. When air and water were present, the purification was more difficult, similar to the case of PP1-AH samples. GC MSD chromatograms and FT-IR spectra indicate a relative high number of various radiation induced impurities which are persistent in the purified fluid.

4 y=Σan xn a0=3.56388 3 a1=-0.80915 a2=0.0492177 0.0768488 |r|=0.997043 2

Absorbance (a.u.) Fig. 25 - UV absorbance at 200 nm as a function 1 of the number of alumina cleaning cycles (static experiment; in every cycle, fresh alumina was used) in the 0 case of PF 5060 γ-irradiated at 28 kGy 0 2 4 6 Number of alumina cleaning cycles - 28 -

Irradiated purified PF 5060 samples (purified PF 5060-28 and purified PF 5060-56) presented a moderate UV optical absorption (higher than DL but lower than PF 5060). This UV optical absorption remained constant when the adsorption treatment was applied, even the GC- MSD and FT-IR indicate the removal of some radiation induced products. Thus, it can be considered that the purification treatment is efficient in the case of PP1, and is satisfactory for DL and other n-C6F14 based fluids. The effectiveness of the adsorption purification is limited by the higher tendency of n-C6F14 molecules to form high molecular weight products, as the two following experimental observations suggested: − the alumina grains used in purification processes of the irradiated samples containing water and air became yellow and lost rapidly their adsorption capacity; it was demonstrated, using indicators dyes, that the large fluorinated molecules are adsorbed on the superficial layer of the alumina granules, thus blocking the active pores; − the distillation process removed a considerable part of the UV optical absorption in both the cases of the irradiated fluids; correspondingly, the distillation residue presented very high UV optical absorption; when adsorption treatment was applied after distillation, the residual UV optical absorption of PF 5060 fluids was completely removed. The quality control of the cooling fluids during their service life can use the polymer, the acidity and the fluorine ions measurements. As a rapid test method is the UV spectrophotometry, which proven its efficiency for purity testing of PP1 fluid. If the absorption at 190 nm is higher than 0.1 absorbance units, it is recommended to perform the polymer, the fluorine and the acidity tests. If the found values fall close or are outside the acceptable limits, it is recommended to change the purification cartridges and repeat the tests. - 29 -

3. CONCLUSIONS

• The studied C6F14 fluids types, in as received state and having impurities introduced in laboratory in controlled concentrations were irradiated using gammas 60Co to 28 kGy and to 56 kGy doses, which are the highest doses expected for certain inner detectors in LHC Experiments; the irradiated fluids were chemically characterized using the following methods and techniques to detect, to identify and to quantify the radiation induced effects: chromatography (GC-MSD and GC-TCD), spectro-photometry (FT- IR, UV-Vis), IS potentiometry, XPS, SEM, EDX, etc. • The induced acidity and the fluorine ion content, the presence of polymers or pre- polymers, the appearance of new chemical species were the main radiation induced effects and these parameters were used to characterize the radiation hardness of the fluids and the influence of the possible impurities present. The impurities added in controlled quantities are the most probable and the typical impurities for such types of fluids. • The air and water presence, as well as the other hydrogen containing molecules during the irradiation process, have strong detrimental effects, including the carbonyl fluoride formation, corrosion and the appearance of the relative high polymeric deposits.

• It was evidenced the higher radiation hardness of PP1 fluid (i-C6F14) as compared to PF 5060 DL (n-C6F14). For similar purity levels, all the radioinduced effects parameters have lower values for PP1 as for DL; the higher radiation resistance of the PP1 is related to the intrinsic resistance of the iso-C6F14 structure: the tertiary carbon seems better protected against radiation effects by the large volume of the branched CF3 group – a situation different of that of similar branched hydrocarbons. The results are also in agreement with the early reported differences of the radiochemical yields for iso-C6F14 and n-C6F14. The average destruction ratio was less as 1 % by mass for the compliant fluids. • The purification tests carried out on less pure, as received fluids, were promising: consequently, the potential suppliers and the acceptable quality of the fluids may be advantageously enlarged. • The cleaning tests on the irradiated fluids have shown a very good efficiency for the as received PP1 fluid (i-C6F14) and an acceptable efficiency for the n-C6F14. • The quality control of the cooling fluids must be assured during their service. The acidity, the fluorine ions and the polymer content controls are recommended. The UV- Vis spectrophotometry can be used as a rapid control method. • The on-line cleaning using activated carbon, alumina and molecular sieves, which efficiently remove the radiation induced impurities, water and greases are recommended. • Prior its charge, the cooling system and the perfluorocarbon fluid must be pumped out and purged with an inert gas to avoid the oxygen and water contamination.

- 30 -

ACKNOWLEDGEMENTS

We acknowledge the strong and valuable support of PH Department. The very competent and accurate measurements and interpretation for SEM and XPS results of Stefano Sgobba, Mauro Taborelli, Gonzalo Arnau Izquierdo, Delphine Letant- Delrieux, Eva Valladolid Gallego in MME Group are gratefully acknowledged. We thank Michele Battistin in CV Group for his continuous support, as well as Pierre Feraudet for his permanent technical help. We acknowledge in particular Corneliu Ponta from IRASM Bucharest for his enthusiast support for the irradiation of our many gaseous and liquid samples and for the precise dosimetry realized.

REFERENCES 1. S. Ilie, R. Setnescu, M. Battistin, B. Teissandier, "Chemical and Radiolytical Characterization of some Perfluorocarbon Fluids Used as Coolants for LHC Experiments - Chemical Characterization", TS-Note-2006-010, October 2006, https://edms.cern.ch/file/804849/1/TS-Note-2006-010.pdf 2. Certificate de compliance for the product PF 5060 3M Performance fluid product ID ZF- 0002-0798-3 (issued by DATE S.A.38770 La Motte d'Aveillans, France) 3. Certificate of Analysis Product PF-5060 DL, Lot. Nbr. 20032/ 13 Mar. 2006 4. Certificate of Analysis Batch No 0294/ Ref. No. P51917 5. AST 427/ 02 Dec. 2005 (ASTOR, Russia) 6. CERN Technical Specification IT-3397/TS 7. "Expected dose for LHC experiments cooling systems" - TS-CV / 2006. 06. 08. 8. CERN Safety Commission - Rapport de Test No SC/CS/65-94-2006 - 65-113-2006 (01.04.2006) 9. Ferreira Marques Antunes L., "Nettoyage des pieces en acier inoxydable" CERN Procedure EDMS Id: 347923 (2002-06-17) 10. IRASM-IFIN-HH - Irradiation Report/ 2006/06.26 11. Allyarov S. R., Gordon D. A., Kim I. P. "Radiolysis of n-perfluoroalkanes and polytetrafluoroethylene" in: J. Fluorine Chemistry 96 (1999), 61 - 64 12. 3M Report no. 201-14684B/ 2003 Aug. 20 / EPA http://www.epa.gov/HPV/pubs/summaries/perfluro/c13244rt.pdf 13. H. Dertinger and H. Jung, "Molecular Radiation Biology", Springer-Verlag, New York, 1969. 14. J.H.O’Donnell and D.F. Sangster, "Principles of Radiation Chemistry", American Elsevier Publishing Company, New York, 1970. 15. L.I. Grossweiner, "The Science of Phototherapy", CRC Press, Boca Raton, 1994. 16. K.G. Zimmer, "Quantitative Radiation Biology", Hafner Publishing Company, New York, 1961. 17. A.J. Swallow, "Radiation Chemistry", John Wiley & Sons, New York, 1973. - 31 -

18. J.W.T. Spinks and R.J. Woods, "An Introduction to Radiation Chemistry", John Wiley & Sons, New York, 1976. 19. Al Malaika, S., "Atmospheric Oxidation and Antioxidants", Ed. G. Scott, vol. I, Elsevier Publishing Company, Amsterdam 1993, Cap 2 20. Hashikawa I., Kawasaki M., Waterland R.L., Hurley M.D., Ball J.C., Wallington T.J., Sulbaek Andersen M.P., Nielsen O.J., "Gas Phase UV and IR Absorption Spectra of CxF2x+1CHO (x = 4)" Journ. Fluorine Chem. 125 (2004) 1925 - 1932 21. Pouchert C.J. (Ed) - "The Aldrich Library of Infrared Spectra" 3rd Ed - Aldrich Chemical Comp. 1981 22. Pacansky J., Waltmann R.J., Jebens D., Heery O., "Electron Beam Induced Degradation of Perfluorinated Ethers: -(CF(CF3)-CF2O)n-, for n = 4, 8 and 50", Journ. Fluorine Chemistry 82 (1997) 85-90 23. Smith D.C., Neilsen J.R., Berryman L.H., Claassen H.H., Houdson R.L., Nav. Res. Lab. Rep. 3567 (1949, cit. in [25]) 24. Hashikawa I., Kawasaki M., Waterland R.L., Hurley M.D., Ball J.C., Wallington T.J., Sulbaek Andersen M.P., Nielsen O.J., "Gas Phase UV and IR Absorption Spectra of CxF2x+1CHO (x = 4)", Journ. Fluorine Chem. 125 (2004) 1925 - 1932 25. Colthup N.B., Daly L.H., Wiberley S.E., "Introduction to Infrared and Raman Spectroscopy" Academic Press Inc, 1990

26. "Tests d'irradiation de C6F14 avec ou sans heptane sur échantillons en acier inoxydable et en aluminium" Rapport no. 98/11/22 (EST/SM/MB/jmD/22.1.98)

27. "Tests d'irradiation du C4F10 liquide ou gazeux sur échantillons en acier inoxydable et en aluminium" Rapport no. 99/05/30 (EST/SM/MB/jmD/31.5.99) 28. S. Ilie - "Irradiation Tests of Perfluorocarbon Cooling Fluids" – CERN, CWG - Nov 1998 29. S. Ilie, C. Petitjean - "Radiation Induced Chemical Effects on some Fluorocarbon Used as Cooling Fluids" SHIM 2002, May 22 - 25, Giardini Naxos, Italy 30. O'Mahony T.K.P., Cox A.P., "Gas chromatographic separation of perfluorocarbons" in: Journ. Chromatog. 637 (1993) 1-11; Turbini L.J., Zado F.M., Elec. Pck. Prod. 20 (1980) 49 31. Patocka J., Bajgar J., "Toxicology of Perfluoroisobutene" in: The ASA Newsletter, Appl. Acience and Analysis Inc. Ed. col. R. Price, 1998 32. Castel. Dehydrators and filters - www.castel.it pag. 92 (2006) 33. Askew W.C., Reed III T.M., Mailen J.C., "Perfluoroalkanes in Ionizing Radiation" in: Radiation Research 33 (1968) 282 - 292 34. ***3M Fluorinert liquids, Product Manual12/97, p 57

- 32 -

ANNEX 1 - Pressure, acidity and fluorine ions content values for the irradiated perfluorocarbon samples

HF equivalent Fluid Pressure (mbar) pH F- (ppm) (ppm) PP1 - 270 5.90 0.042 0.05 PP1-28 - 4.23 1.47 3.39 PP1-56 - 175 4.90 0.63 2.00 PP1-A-28 + 1925 2.59 140 440 PP1-AH-28 - 50 3.82 6.16 15 PP1-AH-56 - 110 3.56 13.70 - DL - 270 5.62 0.092 0.04 DL-28 - 140 3.50 10.5 30 DL-56 - 90 3.44 18 44 PF 5060 - 270 5.43 0.098 0.06 PF 5060-28 - 3.18 23 66 PF 5060-56 + 180 3.36 21 93 PF 5060-A-28 + 1375 2.72 93 155 PF 5060-AH-28 + 95 4.65 1.02 23 PF 5060-AH-56 + 215 - - - PF 5060-HE-28 + 40 3.40 19 78 PF 5060-HE-56 + 100 3.21 22 431 purified PF 5060 - 270 5.54 0.13 0.02 purified PF 5060-28 - 155 3.55 17 47 purified PF 5060-56 - 3.48 19 55

- 33 -

ANNEX 2 - Pre-polymer content values for the irradiated perfluorocarbon samples

Pre-polymer in Sample code Dose (kGy) UV (ref. air) liquid phase (%) 190 PP1 0 0 0.038 PP1-28 28 0.007 0.19 PP1-56 56 < 5.5·10-4 0.047 PP1-A-28 28 0.0015 0.48 PP1-AH-28 28 < 6·10-4 0.95 PP1-AH-56 56 < 6.6·10-4 0.789 PP1-EN-28 28 0.035 - PP1-EN-56 56 - - DL 0 0 0.0319 DL-28 28 0.021 1.61 DL-56 56 0.016 0.67 PF 5060 0 0 0.0462 PF 5060-28 28 0.147 3.32 PF 5060-56 56 0.314 3.90 PF 5060-A-28 28 0.067 - PF 5060-AH-28 28 0.103 2.93 PF 5060-AH-56 56 0.263 - PF 5060-HE-28 28 0.074 2.79 PF 5060-HE-56 56 0.372 3.41 purified PF 5060 0 0 0.0447 purified PF 5060-28 28 0.031 2.14 purified PF 5060-56 56 0.097 2.69

- 34 -

ANNEX 3 - GC-MSD chromatograms of the gas phase of irradiated PP1

Abundance

TIC: NOV9.D\ data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV13.D\data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV42.D\data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Fig. A3.1 - GC-MSD chromatograms of the gas phase of PP1 irradiated samples: Nov9.D: PP1; Nov13.D: PP1-56; Nov42.D: PP1-28.

Abundance

TIC: NOV10. D\ dat a. ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV12. D\ dat a. ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV15. D\ dat a. ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Fig. A3.2 - GC-MSD chromatograms of the gas phase of PP1 irradiated samples: Nov10.D: PP1-AH-28; Nov12.D: PP1-AH-56; Nov15.D: PP1-A-28.

- 35 -

Table A3.1 - GC-MSD analysis of the gas phase of the initial and irradiated PP1 fluids [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

PP1 PP1-28 PP1-56 PP1-A-28 PP1-AH-28 PP1-AH-56 Substance R.T. (min.) (Nov09) (Nov42) (Nov13) (Nov15) (Nov10) (Nov12) CF4 4.12-4.17 - - S S S S C2F6 4.28-4.31 - - S - M S CO2 4.34-4.35 L M - S S S COF2 4.39 - - - M - - CF3H 4.45-4.46 - - - - L M C3F8 4.57-4.61 L L S M M S CF3CF2OCF3 4.77 - L - L L L CF2H-CF3 4.98 - - - - L L C4F10 5.21-5.23 L L M L L M (CF3)3CF 5.50-5.52 L L L L L L cyclo-C5F10 6.20 -6.22 L L L - L L C5F12 6.52-6.53 S S S S S S cyclo-C6F12 8.20-8.25 L L L - L L cyclo-CF3C6F11 8.51-8.53 - - - - L L main peak main peak main peak main peak main peak main peak iso-C F 8.94-8.97 6 14 (99.17 %) (98.54 %) (93.55 %) (92.34) (96.32 %) (89.77 %) n-C6F14 14.65-14.71 L L L L L L C7F16 15.18-15.27 L L L - L L C8F18 16.67-16.90 - L - - L L PFC 25.00-25.22 - L L - L L containing few O

Very small peaks of cyclo-CF3C6F11 and cyclo-C6F12 are observed in PP1 samples as compared to PF 5060 type fluids, where these components are present in important concentrations. The concentration of C5F12 is the major impurity in PP1 fluid. The radiolysis in gaseous phase is more complex when air and water were present (PP1- AH-28 and PP1-AH-56). The presence of H-containing compounds (e.g. CF3H, CF2H-CF3, 1H- perfluoroheptanol, cyclo-C5HF9, H-C6F13 (1-, 2-, or 3- isomers) is evidenced together with a high amount of product located at r.t. ∼ 25 minutes. They can result from the reaction of perfluorocarbon and water radicals.

- 36 -

Abundance

TIC: NOV53.D\ data.ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV21.D\ data.ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV40.D\ data.ms

100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Fig. A3.3 - GC-MSD chromatograms of the irradiated (and purified) PP1 fluid in liquid phase:Nov53.D = PP1; Nov21.D = PP1-28; Nov40.D = PP1-56.

Abundance

TIC: NOV44.D\ data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV45.D\ data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Abundance

TIC: NOV46.D\ data.ms 100000

80000

60000

40000

20000

0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 Time--> Fig. A3.4 - GC-MSD chromatograms of the irradiated (and purified) PP1 fluid in liquid phase: Nov44.D = PP1-A-28; Nov45.D = PP1-AH-28; Nov46.D = PP1-AH-56.

High amounts of C5F12, as well as other perfluorocarbon peaks were found in the liquid phase of the post-irradiation purified samples, irradiated in the presence of air and water, suggesting a more intense scission, by difference when pure PP1 (PP1-56) was irradiated. In the retention time range 0 - 9 minutes, besides the peaks mentioned in the Table A 3.2., there are also several other small peaks corresponding to traces of various substances. In the case of PP1 and PP1-56, no small peaks were observed. In the case of PP1-A-28, there are 10 peaks (total area 0.018 %) which could correspond to various fluorinated molecules containing oxygen atoms (carboxyl acid, ethers, ketones) or fluorinated alkenes. In the case of - 37 -

PP1-AH-28 and PP1-A-56, there are 6 peaks (0.008 % total area) and respectively 7 peaks (0.009 %). Among the possible molecules, there are traces of CF3H, CF3CF2H, CF3CF=CF2 etc. At higher r.t. after 9 minutes (r.t. value for the main component), are several peaks which correspond to higher molecular weight perfluorocarbons as well as to oligomer perfluorcarbon molecules (dimer, trimer...). The last ones can contain also few amounts of H-, O- or double bonds grafted on a perfluorinated structure when and air and water were present. These compounds could be considered as responsible for the observed UV and FT-IR residual absorptions of the post-irradiation purified fluids (see Annex 14 and 15).

Table A3.2 - GC-MSD analysis of the initial and irradiated (purified) PP1 in liquid phase [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

PP1-AH- PP1 PP1-28 PP1-56 PP1-A-28 PP1-AH-56 Substance R.T. (min.) 28 (Nov20) (Nov40) (Nov21) (Nov44) (Nov46) (Nov45) air 4.09-4.10 L L L L L L C2F6 4.28-4.29 - - - - L L C3F8 4.57-4.58 - L L L L L C4F10 5.21 L L L L L L (CF3)3CF 5.50 - L - L - L cyclo-C5F10 6.16-6.19 L L L L L L (CF3)2C=CF2 ? 6.30 - - - - L C5F12 6.48-6.50 M S M M M S cyclo-C6F12 8.01-8.07 L L L L L L cyclo-CF3C6F11 8.14-8.19 L L L L L L main peak main peak main peak main peak main peak main peak iso-C F 8.94-8.97 6 14 (99.32 %) (98.48 %) (98.90 %) (99.06) (98.91 %) (98.19 %) n-C6F14 14.61-14.65 M S M M M S C7F16 15.18-15.20 L M M L L M C8F18 16.73-16.84 - L L L L L substituted PFC 22.14-22.39 - L L L L L substituted PFC 25.00-25.19 - M M M M M substituted PFC 26.27-26.37 L L - L L substituted PFC 26.92-27.00 L L - L L - M substituted PFC 48.91 - - - - - M substituted PFC 50.52-51.40 - - - L - L substituted PFC 54.61 - - - - - L

- 38 -

ANNEX 4 - GC-MSD chromatograms of the PF 5060 DL

Fig. A4.1 - The first part of the GC-MSD chromatograms in the gas phase of the initial and γ-irradiated DL fluid: Nov 64D = DL (initial, unirradiated); Nov 18D = DL-28; Nov 41D = DL-56 (see Table A 4.1. for the peak assignment).

- 39 -

Table A4.1 - GC-MSD analysis of the gas phase of the DL fluid, initial and after irradiation [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]; for comparison, same possible peaks as in the case of irradiated PF 5060 fluid were considered

R.T. DL DL-28 DL-56 Substance (min.) (Nov64) (Nov18) (Nov41) CF4 4.17 - S S C2F6 4.31-4.31 - M S CO2 4.66-4.36 L L L CF3H 4.43-4.47 - - -

C3F8 4.60-4.61 L M M

CF3CF=CF2 4.81-4.91 - L L

C2F5H 4.96-4.99 - L

C4F10 5.21-5.24 L S S CF3CF=CFCF3 5.60-5.63 - - - CF2=CFCF2CF3 5.74-5.78 - - - H, O contg. fluorinated 6.02-6.04 - - - molecule (CF3)2C=CF2 6.44-6.47 - - - C5F12 6.55-6.58 L M M iso-C5F12 6.55-6.57 L L L cyclo-C6F12 8.11-8.15 M M M cyclo-CF3C6F11 8.24-8.25 S S S others peaks with r.t < r.t of 9 peaks; total area: 16 peaks; total area: 13 peaks; total area: . - n-C6F14 0.037 % 0.098 % 0.133 % n-C6F14 (main peak) 9.01-9.05 (98.35 %)* (96.19 %)* (95.98 %)* (CF3)2CFC3F7 11.76-11.86 L L L 2-HC6F13 12.56-12.61 - - L hexane 13.44-13.46 - - - 1-HC6F13 13.75-13.80 - - - C7F16 15.27-15.34 L L L 3H-C6F13 19.19 - 19.26 - - - PFC long chain 22.69-22.77 - L L PFC low H, O content 25.82-25.96 - - L PFC, low O content (ether?) 28.48-28.57 - - - other peaks with r.t. > r.t. of 7 peaks; total area: 7 peaks; total area: 7 peaks; total area: - n-C6F14 0.045 % 0.063 % 0.076 %

Relative few peaks are observed in the GC-MSD spectrum of the gas phase of DL (initial, unirradiated). Most of them correspond to homologues of C6F14 with more than 3 carbon atoms in their molecule. There are also some small ones corresponding to O containing molecules and various perflurocarbon isomers. Irradiation results not only in increasing of the low molecular weight compounds content but also in increasing in high molecular weight products (see the liquid phase analysis). Only few of the high molecular weight were enough volatile to be find in the gaseous phase. The amount of is higher (5- 10 folds) than normal in the irradiated samples, suggesting possible chain scission processes in presence of oxygen traces. Traces of H substituted fluorinated molecules were detected in the irradiated samples; they could appear by interference of traces of water molecules.

Small amounts of CF3CF=CF2 were detected as well in the irradiated fluid.

- 40 -

Abundance

TIC: NOV24.D\data.ms

100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 Time--> Abundance

TIC: NOV26.D\data.ms

100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 Time--> Abundance

TIC: NOV27.D\data.ms

100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 Time--> Fig. A4.2 - GC-MSD chromatograms of the liquid phase of the irradiated DL fluid: Nov62= DL; Nov27 = DL-28; Nov26 = DL-56 (see Table A 4.2. for the peak assignment).

- 41 -

Table A4.2 – GC-MSD analysis of the liquid phase of the DL fluid, initial and after irradiation and cleaning [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

R.T. initial DL-28 DL-56 Substance (min.) (Nov62) (Nov27) (Nov26) air 4.09-4.11 L L L CF4 4.15-4.19 - - - C2F6 4.28-4.29 - - L C3F8 4.58 - L L CF3CF=CF2 4.86-4.87 - - L C2F5H 4.95 - - L C4F10 5.19-5.21 L L-M M CF3CF=CFCF3 5.58 - - - CF2=CFCF2CF3 5.74-5.76 - - - H, O contg. fluorinated molecule 5.99-6.01 - - - C5F12 6.47-6.52 L L-M M iso-C5F12 6.55-6.55 L L L cyclo-C6F12 8.04-8.11 M M M cyclo-CF3C6F11 8.17-8.23 S S S 13 peaks; total area: 8 peaks; total area: 15 peaks; total area: Other peaks with r.t. < r.t. of n-C F - 6 14 0.022 % 0.025 % 0.035 % main peak main peak main peak n-C F 8.67-9.03 6 14 98.59 % 97.71 % 97.36 % (CF3)2CFC3F7 11.72-11.74 L L L 2-HC6F13 12.51-12.57 - L L hexane 13.39-13.45 - - - 1-HC6F13 13.74-13.77 - - - C7F16 15.14-15.29 L M M 3H-C6F13 19.19-19.23 - - - H cont. fluorinated molecule 22.53-22.77 - - - Perfluorinated molecule 23.73-24.03 - - - long fluorocarbonated chain with few 25.77-26.09 - L-M M H, O (as ether, alcohol, acid...) H contg. fluorinated molecule 26.48-26.94 - L M H, O contg. fluorinated molecule 27.44-27.74 - - H and O contg. fluorinated molecule 28.43-28.69 - L L O containing molecule (C=O groups?) 29.69-29.98 - - - Perfluorinated molecule (long chain) 30.21-30.85 - - - Perfluorinated molecule (long chain) 33.67-34.05 - - - Perfluorinate molecule (long chain) 34.26-34.51 - L - 9 peaks; total area: 16 peaks; total: 13 peaks; total area: Other peaks with r.t. > r.t. of n-C F - 6 14 0.187 % area 0.355 % 0.458 %

Few changes are observed in the region of r.t. < r.t. of C6F14, even in the case of small concentration components (called in Table A 4.2 "other peaks with r.t. < r.t. of C6F14"). However, the number of these peaks in the as received fluid is higher than in PP1. It should be noticed also a relative high percent area of the other peaks with r.t. > r.t. of C6F14, in both as received and irradiated DL fluids. There is a relative high peak at 12.21 min. in DL which could be assigned to a C6-C7 perfluorocarbon to explain the relative high value of the others peaks total area. No peaks at r.t. > 16.45 min. were observed. - 42 -

In DL-28, there are two important peaks, one is the above mentioned 12.21 min. and another one is at 14.68 min., which existed in the as received fluid also, which increased after irradiation. Both peaks are attributable to perfluorocarbon molecules. In DL-56, the peak at 12.21 min. decreased slowly, while that at 14.86 reached 0.162 % of the total area. All other peaks at r.t. > 20 min. (pre-polymer) increased in the irradiated DL fluid as compared to the as received one. In DL-56, peaks are evidenced even at r.t. values 46.00 min. (0.079 %) and 49.41 min. (0.042 %). The above data, correlated to PP1 and DL at similar purities suggest an increased susceptibility in the case of n-C6F14 as compared to iso-C6F14 to form high molecular weight molecules (pre-polymers and polymers). The nature of the large size molecules (their structure) seems different to that of similar products resulted from PF 5060: it means less H and O atoms or double bonds included in the fluorocarbonated structure.

- 43 -

ANNEX 5 - GC-MSD chromatograms of pf 5060 irradiated fluid

Fig. A5.1 - GC-MSD chromatograms of the gas phase of the irradiated PF 5060 fluid: Nov33.D = PF 5060; Nov35.D = PF 5060-28; Nov34.D = PF 5060-56 (see Table A 5.1. for the peaks assignment). - 44 -

Fig. A5.2 - GC-MSD chromatograms of the gas phase of irradiated PF 5060 containing various impurities and irradiated at 28 kGy: Nov35.D = PF 5060-28; Nov51.D = PF 5060-A-28; Nov52.D = PF 5060-AH-28; Nov55.D = PF 5060-HE-28 (see Table A 5.1. for the peaks assignment).

- 45 -

Fig. A5.3 - GC-MSD chromatograms of the gas phase of PF 5060 containing various impurities and irradiated at 56 kGy: Nov34.D = PF 5060-56; Nov54.D = PF 5060-AH-56; Nov57.D = PF 5060-HE-56 (see Table A5.1. for the peaks assignment).

- 46 -

Table A5.1 - GC-MSD analysis of the gas phase of the initial and irradiated PF 5060 fluids [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 Substance R.T. (min.) 28 56 A-28 AH-28 AH-56 HE-28 HE-56 (Nov33) (Nov35) (Nov34) (Nov51) (Nov52) (Nov54) (Nov55) (Nov57)

CF4 4.14-4.18 - - S S S S S S

C2F6 4.30-4.32 - - S S M S M S L (masked L (masked L (masked by intense by intense by intense CO 4.33-4.35 L L S M M 2 peak of peak of peak of C2F6) C2F6) C2F6)

CF3H 4.43-4.47 - - S M M M M M

C3F8 4.59-4.61 L L S M M M M M

CF3CF=CF2 4.81-4.91 - L L M L M L L

C2F5H 4.96-4.99 L L M L M M M M

C4F10 5.21-5.24 L L M L M M L M

CF3CF=CFCF3 5.60-5.63 - L L L L L L L

CF2=CFCF2CF3 5.74-5.78 - L L L L L L L H, O contg. fluorinated 6.02-6.04 L L L L L M L molecule

(CF3)2C=CF2 6.44-6.47 - - L - L L - L

C5F12 6.52-6.55 L M M M M M M M iso-C5F12 6.55-6.58 L L L L M L L L cyclo-C6F12 8.11-8.15 M M M M M M M M cyclo-CF3C6F11 8.25-8.29 S S S S S S S S others peaks 5 peaks; 15 peaks; 13 peaks; 11 peaks; 12 peaks; 11 peaks; 11 peaks; 13 peaks; with r.t < r.t. of - total area: total area: total area: total area: total area: total area: total area: total area: n-C6F14 0.023 % 0.038 % 0.141 % 0.060 % 0.129 % 0.086 % 0.087 % 0.170 % main peak main peak main peak main peak main peak main peak main peak main peak n-C F 9.01-9.08 6 14 98.37 % 98.64 % 94.78 % 95.77 % 96.09 % 96.81 % 95.85 % 91.89 %

(CF3)2CFC3F7 11.79-11.81 L L L L L L L L

2-HC6F13 12.56-12.61 L L L L L L L L hexane 13.44-13.46 M L - L L L S S

1-HC6F13 13.75-13.80 - L L L L L L L

C7F16 15.11-15.30 L L L L L L L L

3H-C6F13 19.19-19.26 - L M M L L L M PFC long chain 22.69-22.77 - L L L L L L L PFC low H, O 25.82-25.96 L L L L L L L L content

PFC, low O 28.48-28.57 L L L L L L L L content (ether?)

Other peaks with 1 peak; 1 peak; 5 peaks; 3 peaks; 2 peaks; 3 peaks; 1 peak; 6 peaks; r.t. > r.t. of - A = A = total area: total area: total area: total area: A = A = n-C6F14 0.006 % 0.019 % 0.093 % 0.060 % 0.012 % 0.007 % 0.007 % 0.119 %

- 47 -

The observed radiolysis products (see Tables A 5.1) can be divided in several categories:

− pefluorinated molecules (CF4, C2F6...C7F16 and longer chain perfluorinated molecules);

− unsaturated molecules, with low molecular weight (C3, C4 perfluoroalkens, H containing fluorinated alkenes, e.g. CF=CH-CF3) or high molecular weight compounds (including double bonds containing molecules with r.t. > 20 min.);

− H containing molecules, with low or high molecular weight (e.g. CF3H, C2F5H, 1- HC6F13, 2-HC6F13 a.s.o., including also the molecules containing more than one H atom); − O containing molecules (ethers, carboxylic acids, carbonyl compounds);

− CO2 and COF2; the peaks of these products were sometime screened by the neighboring ones (i.e. C2F6) in the case of PF 5060-HE-56. The concentration of the low molecular weight products and the high molecular weight ones, increased with the irradiation dose. Many small peaks corresponding to various types of low molecular weight products were observed in the irradiated fluids.

Fig. A5.4 - GC-MSD chromatograms of the liquid phase of the post-irradiation purified PF 5060 fluid: Nov58 D = PF 5060; Nov31.D = PF 5060-28 (purified by adsorption); Nov32.D = PF 5060-28, purified by adsorption, then distilled; Nov37.D = PF 5060-56 (see Table A5.2. for the peaks assignment).

- 48 -

Fig. A5.5 - GC-MSD chromatograms of the liquid phase of the following post-irradiation purified PF 5060 fluid samples: Nov32.D = PF 5060-28; Nov56.D = PF 5060-AH-28; Nov59.D = PF 5060-A-28; Nov60. D = PF 5060-HE-28 (see Table A 5.2. for the peaks assignment).

Fig. A5.6 - GC-MSD chromatograms of the liquid phase of the following post-irradiation purified PF 5060 fluid samples: Nov37 = PF 5060-56; Nov65 = PF 5060-HE-56 (see Table A 5.2. for the peaks assignment). - 49 -

Table A5.2 - GC-MSD analysis of the liquid phase of the initial and irradiated and purified PF 5060 fluids [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %] PF 5060 PF 5060 28 distilled PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 PF 5060 Substance R.T. (min.) 28 after 56 purified A-28 AH-28 HE-28 HE-56 (Nov58) (Nov31) purification (Nov37) (Nov59) (Nov56) (Nov60) (Nov65) (Nov32) air 4.09-4.11 L L L L L L L L

CF4 4.15-4.19 L - - - L - L -

C2F6 4.28-4.29 - - - L L L L L

C3F8 4.58 L L - L L L L L

CF3CF=CF2 4.86-4.87 - - - L L L L L

C2F5H 4.95 L - - - L - L L

C4F10 5.19-5.21 L L - L L L L L CF3CF=CFCF3 5.58 - - - L L - - L CF2=CFCF2CF3 5.74-5.76 - - - L L L - L H, O contg. fluorinated 5.99-6.01 L - - - L L - L molecule

C5F12 6.47-6.52 L M L M M M L M iso-C5F12 6.55-6.55 L L L L L L L L cyclo-C6F12 8.04-8.11 M M M M M M M M cyclo-CF3C6F11 8.17-8.23 S S S S S S M S Other peaks with 4 peaks; 6 peaks; 5 peaks; 13 peaks; 17 peaks; 16 peaks; 11 peaks; 16 peaks; r.t. < r.t. of - total area: total area: total area: total area: total area: total area: total area: total area: n-C6F14 0.012 % 0.029 % 0.015 % 0.043 % 0.038 % 0.020 % 0.030 % 0.031 % main main peak main peak main peak main peak main peak main peak main peak n-C F 8.67-9.03 peak 6 14 (98.46 %) (98.17 %) (98.49 %) (98.00 %) (97.84 %) (97.72 %) (98.29 %) (98.18 %)

(CF3)2CFC3F7 11.74-11.80 L L - L L L L L 2-HC6F13 12.51-12.57 - L - L - - L L hexane 13.39-13.45 L - - - - - L L

1-HC6F13 13.74-13.77 - L L L L - - L C7F16 15.18-15.31 M L L L L L L L 3H-C6F13 19.19-19.23 - L L L L L L M H cont. fluorinated 22.53-22.77 - L L L L L L L molecule Perfluorinated 23.73-24.03 L L L L L L L L molecule long fluorocarbonated chain with few 25.77-26.09 L M L M M M L L H, O (as ether, alcohol, acid...) H contg. fluorinated 26.48-26.94 L - L L L L L molecule H, O contg. fluorinated 27.44-27.74 L L L L L L L L molecule H and O contg. fluorinated 28.43-28.69 M M M M M M M M molecule O containing molecule (C=O 29.69-29.98 L L L L L L L L groups?) Perfluorinated molecule (long 30.21-30.85 L - L L L L L L chain) Perfluorinated molecule (long 33.67-34.05 L L L L L L L L chain) Perfluorinate molecule (long 34.26-34.51 L L L L L L L L chain) Other peaks with 2 peaks; 3 peaks; 4 peaks; 8 peaks; 8 peaks; 6 peaks; 4 peaks; 4 peaks; r.t. > r.t. of - total area: total area: total area: total area: total area: total area: total area: total area: n-C6F14 0.018 % 0.037 % 0.073 % 0.112 % 0.086 % 0.057 % 0.041 0.031 %

- 50 -

Most of the significant impurities in the liquid phase of the post-irradiation purified PF 5060 fluid present r.t. values higher than the main component, suggesting a relative high susceptibility of this fluid to form high molecular weight products. There are also traces of many low molecular weight products, which suggest their existence in higher amounts in the irradiated fluid (because of the selective adsorption, part of the resulted molecules are removed during purification). The composition of the post-irradiation purified fluid is close to that of the initial one from point of view of the main component concentration. The most important changes consist in an increase in high molecular weight compounds (the total area of these peaks can reach 0.5 %). - 51 -

ANNEX 6 - GC-MSD chromatograms of the purified PF 5060 irradiated fluid

Fig. A6.1 - GC-MSD chromatograms of the gas phase of the purified PF 5060 irradiated fluid: Nov47.D = purified PF 5060; Nov49.D = purified PF 5060-28; Nov50.D = purified PF 5060-56 (see Table A6.1. for the peaks assignment).

- 52 -

Table A6.1 - GC-MSD analysis of the gas phase of the purified PF 5060 fluid in initial and irradiated state [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

Purified Purified Purified Substance R.T. (min.) PF 5060 PF 5060-28 PF 5060-56 (Nov47) (Nov49) (Nov50) CF4 4.17 - M S C2F6 4.31 - M S CO2 4.36 L L L CF3H 4.46 L L L C3F8 0.212 - M M C4F10 5.24 L M M CF3CF=CFCF3 5.60-5.63 - - - CF2=CFCF2CF3 5.74-5.78 - - - (CF3)2C=CF2 6.44-6.47 - - - C5F12 6.54 M M M iso-C5F12 6.57 L M M cyclo-C6F12 8.12-8.15 M M M cyclo-CF3C6F11 8.25 S S S others peaks with r.t. < r.t. of 6 peaks; total area: 17 peaks; total area: 12 peaks; total area: - n-C6F14 0.022 % 0.079 % 0.043 % main peak main peak main peak n-C F 9.01-9.05 6 14 (98.88 %)* (97.48 %)* (92.70 %)* (CF3)2CFC3F7 11.80-11.81 L L L C7F16 15.27-15.28 L L L 3-HC6F13 19.23 - L long fluorocarbonated chain 25.3 - - L long fluorocarbonated chain 25.7-25.9 L L L long fluorocarbonated chain (n = 12?) with few O (as 28.4-28.6 L L L ether, alcohol, acid...) long fluorocarbonated chain 30.2 - - L long fluorocarbonated chain 32.6 - - L other peaks with r.t. > r.t. of - - 1 peak; 0.08 % 1 peak; A = 0.018 % n-C6F14

Few peaks were observed in the chromatogram of the purified PF 5060 sample (gas phase). The most significant are those of C4-C6 homologues, namely C4F10 and C5F12, cyclo- C6F12 and cyclo-CF3C6F11). No peaks of the perfluorocarbons with less than 4 carbon atoms were observed. The other small peaks were also less important as total area (0.022 %). The peaks structure at r.t. > 20 min. was similar tot that of the PF 5060 (as received). The most important differences as compared to PF 5060 as received were observed in H containing molecules and in low molecular weight perfluorocarbons and O containing molecules concentration. Irradiation determined the formation of relative high amounts of low molecular weight perfluorocarbons. The samples irradiated at 28 kGy and 56 kGy presented intense peaks corresponding to CF4, C2F6 and C3F8. The amount of these compounds increases with the dose. Traces of H-compounds resulted probably from the water traces interference during the perfluorohexane radiolysis. New peaks at r.t. > 20 minutes are observed as a result of irradiation. The process and the products are similar to those observed in the case of PF 5060 and DL.

- 53 -

Fig. A6.2 - GC-MSD chromatograms of the liquid phase of purified PF 5060 irradiated samples: Nov39. D = purified PF 5060; Nov48.D = purified PF 5060-28; Nov63.D = purified PF 5060-56; (see Table A6.2. for the peaks assignment).

- 54 -

Table A6.2 - GC-MSD analysis of the purified PF 5060 liquid, initial and after irradiation and cleaning [L (low) <0.1%; M (medium) 0.1% ...0.4%; S (strong) > 0.4 %]

Purified Purified Purified Substance R.T. (min.) PF 5060 PF 5060-28 PF 5060-56 (Nov39) (Nov48) (Nov63) air 4.09-4.11 L L L CF4 4.15-4.19 - - - C2F6 4.28-4.29 - L L C3F8 4.58 - L L CF3CF=CF2 4.86-4.87 - - - C2F5H 4.95 - - - C4F10 5.19-5.21 L L L CF3CF=CFCF3 5.58 - - - CF2=CFCF2CF3 5.74-5.76 - - - C5F12 6.49-6.52 L L L iso-C5F12 6.52-6.55 L L L cyclo-C6F12 8.03-8.10 M M M cyclo-CF3C6F11 8.17-8.23 S S S 5 peaks; total area: 10 peaks; total area: 11 peaks; total area: others peaks with r.t < r.t of n-C F - . 6 14 0.018 % 0.027 % 0.026 % main peak main peak main peak n-C F 8.97-9.03 6 14 (98.29 %) (98.06 %) (97.88 %) (CF3)2CFC3F7 11.74-11.79 L L L-M 2-HC6F13 12.51-12.57 - - - hexane 13.39-13.45 - - - 1-HC6F13 13.74-13.75 - - - C7F16 15.18-15.28 L M M 3H-C6F13 19.19-19.23 - - - la fel ca la PF 5060 H cont. fluorinated molecule 22.53-22.77 Perfluorinated molecule 23.84-24.00 L L long fluorocarbonated chain with 25.8-26.02 M M M few H, O (as ether, alcohol, acid...) H contg. fluorinated molecule 26.78-27.26 L L L H, O contg. fluorinated molecule 27.52-27.58 L - L Perfluorinated molecule (long chain) 28.60-28.69 M M M few H, O O containing molecule (C=O groups 29.59-29.86 L L L ?) Perfluorinated molecule (long chain) 30.04-30.27 L L L Perfluorinated molecule (long chain) 33.59-33.90 L L L Perfluorinated molecule (long chain) 34.36-34.71 L L L 4 peaks; total area 9 peaks; total area 13 peaks; total area others peaks with r.t < r.t of n-C F - . 6 14 0.028 % 0.173 % 0.388 %

- 55 -

ANNEX 7 - FT-IR spectra of the radioinduced pre-polymers (high molecular weight compounds remained after the evaporation of irradiated fluids)

reference (air) 0.2 PP1-28 DL purifed PF 5060-28 PF 5060-28

0.1 Absorption (abs. units)

0 4000 3000 2000 1000 -1 Wavenumber (cm ) Fig. A7.1 - FT-IR spectra of the evaporation residues of the irradiated (28 kGy) fluids. A higher pre-polymer amount is found in PF 5060-28, and a smaller in PP1-28.

0.35

0.3 Reference air PP1-56 0.25 DL-56 PF 5060-56 0.2

0.15

0.1 Absorbance (abs. units) 0.05

0 4000 3000 2000 1000 -1 Wavenumber (cm ) Fig. A7.2 - FT-IR spectra of the evaporation residues of the irradiated (56 kGy) fluids

- 56 -

0.006

0.004 1211 1190 1240 1035 1147

0.002 4 1023 1314 1320 5 970 3

Absorbance (abs. units) 2 0 1

1300 1200 1100 1000 900 800 -1 Wavenumber (cm ) Fig. A7.3 - FT-IR spectra in the region of 1350 - 750 nm of the evaporation residues of PP1-28, prior and after cleaning: 1 - reference air; 2 - PP1-28; 3 - PP1-28 after purification; 4 - PP1-28 (2.5 folds the amount taken in the curve 2); 5 - PP1-28 after purification (2.5 folds the amount taken in the curve 3). The purification cannot remove the high molecular weight compounds (very small amounts), due to their perfluorinated structure.

1231 1205 0.2 1144 1721 1337

0.1 1787 1384 1834 985 1470 2 813

Absorbance (abs. units) 3 0 1

2000 1500 1000

Wavelength (cm-1 )

Fig. A7.4 - FT-IR spectra in the region of 2000 - 750 cm-1of the evaporation residues of PF 5060-28, prior and after cleaning: 1 - reference air; 2 - PF 5060-28; 3 - PF 5060-28 purified after irradiation (by activated carbon/ molecular sieves/alumina cartridge). It was removed a part of the pre-polymer, namely that containing H-, or O- groups.

- 57 -

1231

0.06 1203

0.04 1142 1273 1026 1344

0.02 1832 982 1462 1392 Absorbance (abs. units) 1726 1786 3

0 1 2 2000 1500 1000

-1 Wavelength (cm ) Fig. A7.5 - FT-IR spectra in the region of 2000 - 750 cm-1 (reference air) of the evaporation residues of PP1-A-28 (2) and PF 5060-A-28 (3). The amount of the resulted pre-polymer is considerably higher in the case of PF 5060-A-28. A smaller pre-polymer amount is formed in the presence of air (compare Figs. 7.4 and 7.5).

0.15

PF 5060-AH-28 1234 1205 PP1-AH-28 Reference air 0.1 1142 2968

0.05 2936 1350 Absorption (abs. units) 981 2877 1468 1786 1720

0 4000 3000 2000 1000

-1 Wavelength (cm ) Fig. A7.6 - FT-IR spectra in the region of 2000 - 750 cm-1 (reference air) of the evaporation residues of PP1-AH-28 and PF 5060-AH-28. The amount of the resulted pre-polymer is considerably higher in the case of PF 5060-AH-28. - 58 -

0.5 1232

PF 5060-AH-56 1205 0.4 PP1-AH-56 Reference air

0.3 1142

0.2 1330 982 1470 Absorbance (abs. units) 0.1 1786 1726

0

2000 1500 1000 Wavelength (cm-1) Fig. A7.7 - FT-IR spectra in the region of 2000 - 750 cm-1 (reference air) of the evaporation residues of PP1-AH- 56 and PF 5060-AH-56. The amount of the resulted pre-polymer is considerably higher in the case of PF 5060-AH-28. The resulted polymer is mainly fluorinated; low amounts of C=C (1786 cm-1) and C=O groups (1726 cm-1), as well as H- (in the case of PF 5060 in 2900 cm-1 region, not shown) are also present.

0.06

PP1-EN-56 1231 PP1-56 Reference air 0.04 1142

0.02 1330 982 Absorbance (abs. units) 822 1844 1460

0 2000 1500 1000

-1 Wavelength (cm ) Fig. A7.8 - FT-IR spectra in the region of 2000 - 750 cm-1 of the evaporation residues of PP1-HE-56 and PP1-56. The presence of an unsaturated compound increased the amount of the pre-polymer; the nature of the pre- polymer is basically the same (a weak characteristic band at 1844 cm-1 and the lack of the peaks in the region of 1700 - 1800 region are to be remarked).

- 59 -

PF 5060-HE-56 1231 0.6 PF 5060-56 1205 Reference air

0.4 1142

0.2 1347 1470 1383 982 Absorbance (abs. units)

0 2000 1500 1000

-1 Wavelength (cm ) Fig. A7.9 - FT-IR spectra in the region of 2000 - 750 cm-1 of the evaporation residues of PF 5060-HE-56 and PF 5060-56. Hexane induced an increased amount of pre-polymer. - 60 -

ANNEX 8 - Mass evaluation of the radiation-induced deposits on the metallic strips surface

Observations on the Aluminum Stainless steel Sample code strip state* Δm Δm Δm Δm Stainless No. No. Alu (mg) (%) (mg) (%) steel PP1-56 45 - 0.3 - 0.011 32 0 0 A A DL-28 40 - - 31 - - - - DL-56 28 0.3 0.011 28 0.2 0.003 A B PF 5060-56 36 2.9 0.10 37 0.6 0.008 A B purified PF 5060-28 41 2.8 0.103 41 0.5 0.007 B B purified PF 5060-56 31 0 0 34 - 18.2 0.25 A B PP1-A-28 38 0.7 0.026 27 0.2 0.003 A B PP1-AH-28 30 - - 33 - - D D PP1-AH-56 34 221.8 - 7.90 26 42.5 0.592 D D PP1-EN-28 35 1.3 0.048 35 0 0 A B PP1-EN-56 37 0 0 44 0 0 A A PF 5060-A-28 46 - - 39 - - - - PF 5060-AH-28 44 135.2 4.89 38 30.7 0.433 D D PF 5060-AH-56 26 172.6 6.141 43 18.7 0.263 D D PF 5060-HE-28 33 1.7 0.054 36 0.5 0.007 A C PF 5060-HE-56 27 1.7 0.061 30 0.5 0.007 A C

* A = no visible corrosion traces; B = slight corrosion; C = moderate corrosion; D = intense corrosion

Strip surface: 34.6 cm2 - 61 -

ANNEX 9 - Optical (visual) inspection of the irradiated metallic strips No visual differences between the initial and the irradiated strips were observed in the case of the samples marked A or B in the Annex 8. The situation was different for the strips irradiated in the presence of air and water. A surprising high corrosion together with polymer deposits on the metallic strips were observed in this case, both for PP1 and PF 5060 as received. In spite of the relative low amounts of the mentioned impurities - air 1 atm, water 0.5 mL (~ 600 ppm) - abundant, white deposits resulted on the aluminum strips and an intense corrosion was observed on the stainless steel strips. Similar effects were observed in both PP1 and PF 5060 irradiated in the presence of air and water and the most representative pictures are shown and commented below. The thickness of the deposit on the aluminum strip in the sample PP1-HA-56 is suggested by Figs. A9.1 - A9.4, which show optical transversal images of a sample. The deposits are more abundant on the strip portion exposed to the irradiated gas phase, especially at the interface liquid / gas and the upper part of the strip. In this region, the thickness exceeds 2 mm. Lower deposits and more uniform thicknesses are observed on the liquid immersed part of the strip. The deposits on aluminum are not adherents, especially in the region exposed to the gas phase and can consist in aluminum oxide and fluoride. However, in this region, the metal seems not corroded. (Fig. A9.5). The deposit in gas phase is not compact; many bubbles originate probably from gas evolution (low molecular weight perfluorocarbons, hydrogen or other gases) (Fig. A9.6). In the liquid phase (Fig. A9.7), the deposit appears more compact than in the gas phase; the presence of some cracks suggests a lack of adherence specific for the fluorinated polymers [9.1]. In the case of the stainless steel sample, an intense dark-gray coloration was observed. It is more intense and uniform in the immersed region and clearly decreased to the upper part of the strip (Fig. A9.8). The deposits are different to those observed in the case of aluminum samples and seem to be caused by corrosion. Brown and green rounded particles, attributable to metallic salts, fluorides probably, are observed on the strip surface (Fig. A9.9). Their distribution is non uniform. In the gaseous phase, the diameter of the green crystals is 2-3 folds greater than in the liquid phase. The number of these crystals (particles) is the highest at the interface, both in gas and in liquid phase (Fig. A9.9). The concentration of these crystals decreases to the strip extremities (Fig A.9.9 - a. 9.11). Small white deposits (probably perfluorinated polymer) can be also observed (Fig. A9.9-A9.11) in all the regions, but considerably lower than on the aluminum surface. - 62 -

Reference 9.1. Samyn P., Schoukens G., Quintelier J., De Baets J., "Friction, wear and material transfer of sintered polyimides sliding against various steel and diamond-like carbon coated surfaces Tribology International" 39 (2006) 575–589

Fig. A9.1 - A9.4: Alu (34) strip irradiated in PP1-AH-56 - transversal photo against to a ruler (1 div. = 1 mm)

gas liquid

Fig. A9.1 - The interface liquid-gas

Fig. A9.2 - The region at the half distance between the liquid surface and the top of the strip (gaseous phase)

Fig. A9.3 - The region at the top part of the trip (gas phase) - 63 -

Fig. A9.4 – The immersed part of the strip

Fig. A9.5 - A region near to the interface with partially taken-off deposit on Alu (34) strip irradiated in PP1-AH-56

- 64 -

Fig. A9.6 - Micrograph of the strip Alu (34) irradiated in PP1-AH-56 - the gas phase irradiated region.

Fig. A9.7 - Micrograph of the strip Alu (34) irradiated in PP1-AH-56 - deposit in the liquid phase irradiated region

- 65 -

gas

liquid

gas liquid

Fig. A9.8 - Inox (26) strip from PP1-AH-56

gas

liquid

Fig. A9.9 - Micrograph of the interface area region of the stainless steel (26) strip irradiated in PP1-AH-56.

- 66 -

ANNEX 10 - SEM and EDX inspection of the irradiated metallic strips

Inox reference PF 5060-HE-28 PF 5060-HE-56

Fig. A10.1 - Comparative SEM images of the following stainless steel strips: initial (strip no. 13 ss), PF-5060-HE-28 (strip no. 36 ss) and PF-5060-HE-56 (strip no. 30 ss). The higher irradiation dose results in formation of white insulated deposits, not visible at 28 kGy. The elemental analysis suggests the presence of the fluorinated polymers (see the Table below).

- 67 -

Aluminum reference PF 5060-HE-28 PF 5060-HE-56

Fig. A10.2 - Comparative SEM images of the following aluminum strips: initial (strip no. 47 alu), PF-5060-HE-56 (strip no. 33 alu), PP1-56 (strip no. 45 alu). Deposits of pin-shaped fine particles are observed on both PF-5060-HE-28 and PF-5060HE-56 strips; higher amount seems present at 56 kGy. Isolated white deposits are also observed on PF-5060HE-56 strip. - 68 -

Reference stainless steel (no. 19) PP1-56 DL-56

Fig. A10.3 - Comparative SEM images of the following stainless steel strips: initial (strip 19 ss), PP1-56 (strip no 32 ss) and DL-56 (strip 28 ss). The separation between crystallites is less clear in the case of the irradiated strips immersed in liquid.

- 69 -

Reference aluminium PP1-56 DL-56 purified PF5060-28 (no. 47)

Fig. A10.4 - Comparative SEM images of the following aluminum strips: initial (strip 47 alu), PP1-56 (strip no 27 ss) DL-56 (strip 28 alu) and purified PF 5060-28 (strip 41 alu). The surface of the irradiated in liquid phase samples is smoother, due perhaps to a protective oxide or fluorine layer; the layer appears very thin in the case of PP1-56 and thicker for DL-56. PF 5060-28 is covered by a relative thick layer with many cracks.

- 70 -

PP1-A-28 PP1-AH-56 PF 5060-AH-56

Fig. A10.5 - Comparative SEM images of the following stainless steel strips: PP1-A-28 (strip no. 27 ss), PP1-AH-56 (strip no. 26 ss) and PF 5060-AH-56 (strip no. 43 ss). The strip 27 (PP1-A-28) has less deposits and the crystallites are still visible. Abundant deposits are observed both in the cases of PP1-AH-56 and PF 5060-AH-56.

Fig. A10.6 - SEM images of a ss strip immersed and irradiated with PP1-AH-56; several layers are observed; oxides and metal salts have different shapes (see also Fig. A10.5); the white rounded particles are probably fluorinated polymers.

- 71 -

PP1-AH-56 PF 5060-AH-56

Fig. A10.7 - Comparative SEM images of the aluminum strips immersed and irradiated in PP1-AH-56 and PF 5060-AH-56; the presence of at least two different layers can be observed; a thick and non- adherent oxide or fluoride layer covers the metal; polymer particles are deposed on the inorganic layer.

PP1-A-28 PP1-AH-56 PF 5060-AH-56

Fig. A10.8 - Comparative SEM images of the following aluminum strips: PP1-A-28 (strip no. 38 alu), PP1-AH-56 (strip no. 34 alu) and PF 5060-AH-56 (strip no. 26 alu). The surface of the PP1-A-28 immersed strip is covered by a thin layer of a deposit which may be a fluorinated polymer taking into account its waxy appearance. Polymer deposits are more abundant, in PF 5060-AH-56 as compared to PP1-AH-56; is to be noticed the pin shaped parts present.

- 72 -

Fig. 10.9 - SEM images of the deposits on a PF 5060-AH-56 aluminum strip (no. 26 alu)

- 73 -

PP1-AH-28 PF 5060-AH-28

Fig. A10.10 - Comparative SEM images of the deposits on PP1-AH-28 (no. 30 ss) and PF 5060-AH-28 (no. 26 ss) stainless steel strips. Similar deposits as shown for 56 kGy irradiated samples can be observed. White particles are fluorinated polymer.

- 74 -

PP1-AH-28 PF 5060-AH-28

Fig. A10.11 - Comparative micrographs of the deposits on PP1-A-28 (no. 30) and PF 5060-28 (no. 44) aluminum strips.

Table A10.1 - The elemental composition of some radiation induced deposits on stainless steel strips as resulted from EDX measurements

No. Sample code C F Mean Stdv Mean Stdv 13 ss - - - - - 32 ss PP1-56 15.4 0.5 13.5 1.9 27 ss PP1-28 20 0.5 10.4 1.1 36a ss PF 5060-HE-28 9.6 0.4 53.6 1.5 36b ss PF 5060-HE-28 12.5 0.4 47.7 1.1 30 ss PF 5060-HE-56 19.1 4.4 52.2 1.7

- 75 -

ANNEX 11 - Perfluoroisobutylene properties

CAS Number: 382-21-8 Synonyms related: Octafluoroisobutylene Isobutene, octafluoro- 1,1,3,3,3-Pentafluoro-2-trifluoromethyl-1-propene 1-Propene, 1,1,3,3,3-pentafluoro-2-trifluoromethyl- Octafluoro-sec-butene PFIB

Chemical formula: C4F8

F3C Chemical structure: C CF2 F3C

Molecular weight: 200.0

Physical properties: - Boiling point : 7 °C - Density : 1.6 g/L - Colorless gas

Generalities PFIB is a strong electrophilic molecule, which reacts with all nucleophiles [11.1, 11.2]. The high electrophilic character of PFIB is a result of the strong electron-attracting effects of the fluorine atoms of the trifluoromethyl groups and the conjugation of the fluorine’s p electrons with the double bond of the vinyl group. Several reactive intermediate species were identified in the reaction of PFIB with nitrone and nitroso spin trap agents, and, some of the expected reactive nucleophiles in vivo include amines, alcohols and especially thiols [11.3]. PFIB decomposes rapidly when dissolved in water, forming various reactive intermediates and fluorophosgene, which then decomposes into carbon dioxide, a radical anion and hydrogen fluoride [11.4]. PFIB is a gas with a boiling point of 7.0 °C at one atm and a gas density of 8.2 g/ L [11.5]. This substance is known to result as a by-product in tetrafluoroethylene production and during thermal degradation of polytetrafluoroethylene (PTFE/Teflon(R)) at approximately 425°C. The occupational exposure limit value should not be exceeded during any part of the working exposure. The symptoms of lung edema often do not become manifest until a few hours have passed and they are aggravated by physical effort. Rest and medical observation are therefore essential. Immediate administration of an appropriate inhalation therapy by a doctor or a person authorized by him/her, should be considered.

- 76 -

Toxicity The toxicity of PFIB may be correlated with its susceptibility to nucleophilic attack and the generation of reactive intermediates [11.1]. − median lethal concentration (LC50) in single exposures of rats: 0.5 ppm.; the intoxicated rats either died with gross pathological signs of pulmonary congestion or recovered with no apparent residual effects; − 5-second LC50 was 361 ppm; − 10-minutes LC50 was 17 ppm [11.5]. Similar high acute toxicity following inhalation was seen in other species with a two hour LC50 in mice reported to be 1.6 ppm [11.5], in rabbits 1.2 ppm [11.6], in guinea-pigs 1.05 ppm [11.7] and in cats 3.1 ppm [11.7]. In experiments in which rats were exposed to a concentration of 12.2 ppm for 10 min, a postexposure latency period of approximately 8 hours was observed prior to the occurrence of pulmonary edema [11.8]. Occupational exposure limits: ACGIH TLV 2004: 0.01 ppm, 0.082 mg/m3 - ceiling value [11.9]. Inhalation symptoms: sore throat; cough, nausea, headache, weakness, shortness of breath, laboured breathing (symptoms may be delayed) [11.10]. Prevention [11.10]: • inhalation: ventilation, local exhaust, or breathing protection, • skin: protective gloves, • eyes: safety spectacles. First aid: • on inhalation: fresh air, rest; half-upright position; artificial respiration may be needed; refer for medical attention; • on skin contact: first rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor [11.10].

References 11.1. Zeifman, Y.B., Ter-Gabrielyan, N.P., Knunyants, I.L. The Chemistry of Perfluoroisobutylene. Uspekhi Khimii, 1984; 53: 431-461. 11.2. England, D.C., Krespan, C.G. Fluoroketenes. I. Bis(trifluoromethyl)ketene and Its Reaction with Fluoride Ion. J Am Chem Soc, 1966; 88: 5582-5587. 11.3. Arroyo, C.M. The Chemistry of Perfluoroisobutylene (PFIB) with Nitrone and Nitroso Spin Traps: an EPR/Spin Trapping Study. Chem Biol Interact 1997; 105: 119-129. 11.4 Lailey, A.F., Hill, L., Lawston, I.W., Stanton, D., Upshall, D.G. Protection by Cysteine Esters Against Chemically Induced Pulmonary Oedema. Biochem Pharmacol 1991; 42: PS47-52. 11.5. Smith, L.W., Gardner, R.J., Kennedy, G.L., Jr. Short-Term Inhalation Toxicity of Perfluoroisobutylene. Drug Chem Toxicol 1982; 5: 295-303. 11.6. Karpov, B.D. Determination of Upper and Lower Parameters of Perfluoroisobutylene Toxicity. Tr. Leningr Sanit Gig Med Inst 1975; 30: 111-120. - 77 -

11.7. Paulet, G., Bernard, J.P. High Boilers Appearing During the Production of Polyfluorethylene. Biol Med 1968; 57: 247-301. 11.8. Lehnert, B.E., Archuleta, D., Gurley, L.R., Session, W., Behr, M.J., Lehnert, N.M., Stavert, D.M. Exercise Potentiation of Lung Injury Following Inhalation of a Pneumoedematogenic Gas: Perfluoroisobutylene. Exp Lung Res 1995; 21: 331-350. 11.9. US Department of Labor, Occupational Safety & Health Administration, http://www.osha.gov/dts/chemicalsampling/data/CH_260750.html 11.10. IPCS INCHEM, Perfluoroisobutylene ICSC 1212, http://www.inchem.org/documents/icsc/icsc/eics1216.htm

- 78 -

ANNEX 12 - Carbonyl fluoride properties

CAS Number: 353-50-4 Synonyms related: Carbon difluoride oxide Carbon fluoride oxide Carbon oxyfluoride Carbonyl difluoride Fluoroformyl fluoride Fluorophosgene

Chemical formula: CF2O

F Chemical structure: O=C F

Molecular weight: 66

Physical properties: - colorless gas with a pungent and very irritating odor. (Note: shipped as a liquefied compressed gas). - vapor pressure : 55.4 bar; - boiling point : -83 °C; - melting point : -114 °C; - relative density (water = 1) : 1.39 (at -190 °C) - density : 2.89 g/ L - relative vapour density (air = 1) : 2.3 - solubility in water : reaction (COF2 + H2O → CO2 + H2O)

Generalities

- COF2 is used in organic synthesis and is generated from the thermal degradation of fluoropolymers (e.g., polytetrafluoroethylene (PTFE) and polyfluoroethylenepropylene) as well as from their radiation induced degradation in presence of air.

- Liquid COF2 is a severe skin irritant. Toxic effects are due to the liberation of hydrogen fluoride by hydrolysis. COF2 inhalation causes pulmonary edema in animals exposed to lethal concentrations and liver and kidney damage in subchronic studies. Possible frostbite from contact with liquid.

Toxicity Occupational exposure limits [12.1]: − TLV (threshold limit value, ACGIH), 2 ppm; TWA limit: 2 ppm for 8 h [12.4]; − STEL (short term - 15 min. [12.4] - exposure limit, ACGIH) 5 ppm; − Occupational Exposure Limit in Switzerland: MAK- week 2 ppm (5 mg/m3), JAN1999 [12.2]; − Occupational Exposure Limit - France: VME 2 ppm (5 mg/m3), JAN1999 [12.2]. - 79 -

Symptoms [12.1]: − inhalation: burning sensation, sore throat, cough, labored breathing, shortness of breath; symptoms may be delayed; − skin contact: frostbite, redness, pain; − eyes: redness, pain, blurred vision, severe deep burns. Prevention [12.1]: − inhalation: ventilation, local exhaust, or breathing protection; − skin contact: wear appropriate chemical resistant gloves [12.3], protective clothing; − eyes: face shield, or eye protection in combination with breathing protection. Firs aid [12.1]: − on inhalation: fresh air, rest, half-upright position, artificial respiration may be needed; refer for medical attention [12.1]; − on frostbite: rinse with plenty of water, do not remove clothes; refer for medical attention; − on eyes: first rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.

References 12.1. NIOSH, International Chemical Safety Cards: Carbonyl fluoride-ICSC: 0633, 2003, Nov. 24 http://www.cdc.gov/niosh/ipcsneng/neng0633.html 12.2. NIOSH, The Registry of Toxic Effects of Chemical Substances, Carbonyl fluoride, RTECS #: FG6125000, Aug. 2006, http://www.cdc.gov/niosh/rtecs/fg5d75c8.html 12.3. Matheson Trigas, Carbonyl fluoride MSDS, Jan 24, 1989, rev. Jan. 01, 2007, http://www.mathesontrigas.com/pdfs/msds/MAT04320.pdf 12.4. OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. http://www.cdc.gov/niosh/pel88/353-50.html

- 80 -

ANNEX 13 - Purification tests on the as received pf 5060 fluid

Objectives: − efficiency assessment of the various activated carbon materials to remove the hydrogen containing molecules; − evaluation of the effectiveness of other adsorbers; − evaluation of the effectiveness of the purifying materials in removal of other molecules, such as H-substituted perfluoroalkanes and perfluoroalkenes; − set-up a laboratory purification system; − in laboratory purification of an as received PF 5060 fluid and its characterization.

Materials Activated carbon: − Riedel-de-Haen (Sigma-Aldrich Laborchemikalien GmbH, Seelze, Germany) 18002, lot no. 43210, CAS no. 64365-11-3, EC no. 264-846-4 - Charcoal activated purrum (loss on drying ≤ 10 % at 120°C; Ignition residue: ≤ 7%); − Fluka 96831 (Fluka Chemie GmbH Buchs, lot no. 120 6149 6250 5038; CM 12.01 (7740-44-0, produced in USA), grains, recommended "for removing organic impurities from aqueous solution in electroplating and in drug research"; − Fluka 39988, (Fluka Chemie GmbH Buchs produced in Netherlands lot 412 531/1 442 05 240 CM 12.01), "recommended for decolorizing; suitable as carrier material for catalysts", steam activated and acid washed rods, diameter 0.8 mm; water < 0.5 %; Fe ≤ 200 ppm; − Vegetal charcoal Prolabo (Prolabo, Fontenay S/Bois) 22 631 lot 171 VO (Charcoal vegetable activated, granular; 3 mm); cendres max. 12%; H2O max. 10%; − Fluka 29238 (Fluka Chemie GmbH Buchs, lot & filling code 402138/1/34704302, produced in Switzeland, ), rods φ = 3 mm, neutralisation capacity > 2 meq. acid/g; − Supelco (Supelco Park, Bellefonte, PA, USA) 2-2451 lot 1252036 (Replacement charcoal for chromatographic use).

Methods Purification was performed in static tests (mixing of the activated carbon with the liquid in an adequate vessel and subsequent filtration) or in dynamic mode using a filtering cartridge (Fig. A13.1). FT-IR spectroscopy (the peaks in the region of 2800 - 3000 cm-1 region), UV-vis spectrophotometry (the absorbance at 190 nm) and GC-MSD were used to compare the purified PF 5060 and the as received PF 5060.

Results Fig. A 13.2, A 13.3 and A13.4 show that all activated carbon were effective in H- containing molecules removal. The most effective appears Fluka 39988 and Fluka 96831 (see the absorbance values in Table A 13.2). The efficiency of the activated carbon is different depending on their type; Supelco, Fluka 39388 and Fluka 96831 appear the most efficient. The treatment with activated carbon efficiently removed the H-containing molecules; the purified fluid contained less hydrogen than the fluid considered as pure and taken as reference (Fig. A 13.4). - 81 -

When the contact time was shorter, the efficiency was different, e.g. Supelco was less efficient than Fluka 39988. The laboratory purification system was based on activated carbon (Fluka 39988). Other components were added in order to remove the water traces (molecular sieves and silica) and the solved CO2 (KOH). The purified fluid was characterized by FT-IR (Fig. 13.5), UV-vis (Fig. 13.6) and GC- MSD (see the Annex 6 for purified PF 5060 and, for comparison, the Annexes 3-5); the results indicate that the purified PF 5060 is comparable to PP1 and DL.

liquid outlet (purified) Teflon/PP filter

Activated carbon 70 cm3 (11 cm)

KOH + molecular sieves 13 cm3 (2 cm)

Activated carbon 10 cm3 (1.5 cm)

Activated SiO2

26 cm3 (4 cm)

Activated carbon 26 cm3 (4 cm)

Teflon/PP filter liquid inlet

Fig. 13.1 - The structure of the cartridge used for laboratory purification of the as received PF 5060 fluid

- 82 -

0.1

7 0.05 6 5 4 0 1 Absorbance (abs. units)

3 2 -0.05 3200 3100 3000 2900 2800 -1 Wavenumber (cm ) Fig. A13.2 - FT-IR spectra of the PF 5060 fluid treated by activated carbon (ca. 2g activated carbon, 50 mL fluid, 1.5 h): 1 - reference air; 2 - Supelco; 3 - Fluka 39988; 4 - Fluka 96931; 5 - Riedel de Haen; 6 - Prolabo (vegetal activated charcoal).

0.15

0.1 2

0.05

1

Absorbance (abs. units) 0 5

3 4 -0.05 3200 3100 3000 2900 2800 2700

Wavenumber (cm-1 )

Fig. A13.3 - FT-IR spectra of the PF 5060 fluid treated by activated carbon (ca. 2g activated carbon, 50 mL fluid, 1.5 h): 1 - reference PF 5060 as received; 2 - Supelco; 3 - Fluka 39988; 4 - Fluka 96931; 5 - Riedel de Haen; 6 - Prolabo (vegetal activated charcoal).

- 83 -

0.1

7 0.05 6 5 4 0 1 Absorbance (abs. units)

3 2 -0.05 3200 3100 3000 2900 2800 -1 Wavenumber (cm ) Fig. A13.4 - FT-IR spectra of the PF 5060 fluid treated by activated carbon (ca. 2g activated carbon, 50 mL fluid, 15 minutes): 1 - reference C6F14 with partially eliminated H-compounds (by evaporation); 2 - Fluka 39988; 3 - Fluka 96831; 4 - Fluka 29204; 5 - Riedel de Haen; 6 - Supelco; 7- untreated.

0.15

0.1 2

0.05

1

Absorbance (abs. units) 0 5

3 4 -0.05 3200 3100 3000 2900 2800 2700

Wavenumber (cm-1 )

Fig. A13.5 - The effect of purification of the as received PF 5060; FT-IR spectra in region 3200 - 2700 cm-1 : 1 - reference air; 2 - PF 5060 as received; 3 - purified PF 5060; for comparison: 4 - PP1; 5 – DL.

- 84 -

0.15

0.1

4 0.05 2

3 5 0 1 Absorbance (abs. units)

-0.05 200 220 240 260

Wavelength (nm)

Fig. A13.6 - The effect of purification on the UV absorbance of the PF 5060 as received: 1 - reference air; 2 - PF 5060 as received; 3 - purified PF 5060; for comparison: 4 - PF 5060 + 15 min. Fluka 39388; 5 - PP1. - 85 -

ANNEX 14 - Purification tests on the irradiated fluids

Objectives − Testing of some possible solutions to maintain the quality of the fluid during its service by removal of the radiation induced impurities. − Characterization of the purified fluids.

Materials The effectiveness of various purifiers, listed below, was tested: − activated alumina: Alumina oxide for drying (Fluka 06400, size 2-5 mm, lot & filling code 1122962/ 33606013, produced in USA) and aluminum oxide Fluka for chromatography (Fluka 06290; particle size: 0.05 - 0.15 mm; pH = 9.5, produced in Switzerland); − Molecular sieves UOP type 13X (Fluka 69855, pore diameter 10 Å, lot & filling code: 1080520/ 11706141, produced in Italy); − activated silica: Silica for drying (particle size 2-3 mm, with indicator), and Silica for chromatography (Acros Organics, particle size 0.06 - 0.2 mm, code 241660010, lot no. A0230465, product of CN); − activated carbon: • Riedel-de-Haen (Sigma-Aldrich Laborchemikalien GmbH, Seelze, Germany) 18002, lot no. 43210, CAS no. 64365-11-3, EC no. 264-846-4 - Charcoal activated purrum (loss on drying ≤ 10 % at 120°C; Ignition residue: ≤ 7%); • Fluka 96831 (Fluka Chemie GmbH Buchs, lot no. 120 6149 6250 5038; CM 12.01 (7740-44-0, produced in USA), grains, recommended "for removing organic impurities from aqueous solution in electroplating and in drug research"; • Fluka 39988, (Fluka Chemie GmbH Buchs produced in Netherlands lot 412 531/1 442 05 240 CM 12.01), "recommended for decolorizing; suitable as carrier material for catalysts", steam activated and acid washed rods, diameter 0.8 mm; water < 0.5 %; Fe ≤ 200 ppm; • Fluka 29204 (Fluka Chemie GmbH Buchs, produced in Switzerland, lot & filling code: 402136/1 4250 3135; CM 12.01 ), recommended "for the purification of gas; steam activated rods; loss on drying ≤ 5%; diameter ca. 3 mm, butane adsorption (p/p0 = 0.1) 18 - 20%; • Vegetal charcoal Prolabo (Prolabo, Fontenay S/Bois) 22 631 lot 171 VO (Charcoal vegetable activated, granular; 3 mm); cendres max. 12%; H2O max. 10%; • Fluka 05113 (lot & filling code:1257557/ 438061160, produced in USA), size 0.5 - 1 mm, for chromatography use; • Fluka 29238 (Fluka Chemie GmbH Buchs, lot & filling code 402138/1/34704302, produced in Switzeland, ), rods φ = 3 mm, neutralisation capacity > 2 meq. acid/g.

Methods Static tests were carried out by stirring the purifier (2-4 g) together with the irradiated fluid (10-15 mL) to test the efficiency of each purifier. Continuous (circulating) tests were performed using a laboratory installation equipped with one or two cartridges as it is schematically shown in Fig. A14-1. - 86 -

Sample taking out

Supplementary cartridge (optionally used)

Sample taking out

Cartridge activated carbon/molecular sieves/alumina

C6F14 tank Circulating (V = 1 L) pump

Fig. A14.1 – Schematic view of the installation used for laboratory purification of C6F14 fluids

The purification effect was tested by UV spectrophotometry, as a rapid test, by measuring the optical absorption at 190 nm, the abscise intercept and the peak surface at. 190 nm. The purified fluids resulted from continuous tests were also characterized by GC-MSD (Annexes 3 - 6), FT-IR (Annex 15), potentiometric determination of acidity and free fluorine content, and gravimetry (for pre-polymer content determination).

Results A. Static purification tests For irradiated PP1-28, the effectiveness of the activated carbon was quite similar, irrespective of the carbon type (Fig. A14.2). Because the optical absorption decreased up to the value corresponding to the PP1 as received, it can be considered that carbon purifiers are effective in this case. For PF 5060-28, the effectiveness of the activated carbon depended on the carbon type; the most efficient were Fluka 96831 and Fluka 39388 (A14.3). Even a significant decrease is observed (especially in the peak area) the optical absorbance at 190 nm remains high enough. This residual absorption can be due to impurity traces with high molar extinction coefficients or to double bonds grafted on high molecular weight fluorocarbon molecules. For purified PF 5060-28, no significant changes in the optical UV absorbance is observed after the activated carbon treatment; this behavior suggests that the double bonds are grafted on large perfluorinated structures which slightly interact with the active carbon (Fig. A14.4). The KOH impregnated carbon (Fluka 29204) resulted in higher optical absorption as compared to the single carbon treated fluid (Fig. A14.5). - 87 -

Alumina, molecular sieves and silicagel are known to be efficient as both driers and purifiers; hence, the purification efficiency of materials was tested on the irradiated fluids. The studied purifiers were efficient in purification of PP1; the efficiency of alumina for chromatography is close to that of Fluka 39988 (Fig. A14.6). For PF 5060-28, only part of the UV optical absorption was removed; alumina and silica, both for chromatography use, were the most effective (Fig. 14.7). Repeated treatment with alumina reduced significantly the UV optical absorption of PF 5060-28 (Fig. A14.8). No significant changes in the UV optical absorption were observed when other purifiers are used after repeated alumina treatment (6x10'), except a slight decrease in the case of KMnO4 and vegetal charcoal treatment; this behavior suggests that part of the UV optical absorption is due to oxidable groups (Fig. A14.9), such as C=C. The alumina particles (drier or chromatographic) became yellow after using in purification process. Laboratory magnifier examination of the alumina drier particles shows that they are covered by a continuous thin layer which silts the pores; hence the adsorption is not possible and the dye is not observed inside when such pellets are immersed in a dye solution (Fig. A14.12). No activity of thermally treated alumina that high molecular weight compounds are involved in silting process (Fig. A14.9). For purified PF 5060-28, the absorbance of the irradiated fluid changed a little after the treatments with alumina or silica for chromatography. Other materials were practically not efficient (Fig. A14.11). Distillation was also applied, single or combined with purifiers treatment, to remove the high molecular weight component; it was observed that most of the UV optical absorption remained in the distillation residue (Fig. A14.13 and A14.14). The curves shown in Fig. A 14.15 confirm also show that the re-dissolved (in DL as received) residue of DL-28 presented similar optical UV absorbance as DL-28 so, the responsible groups are grafted on non-volatile molecules. Slight decrease in optical absorbance of the distilled DL-28 after subsequent treatment by alumina or activated carbon was observed as well (Fig. A14.17). Therefore, it can be assumed that the scission of C6F14 un-branched structure led to perfluoroalkenes which subsequently polymerize resulting high molecular weight compounds which contain one ore more double bonds. Similarly to low molecular weight perfluoroalkenes, these molecules interact slightly with the purifiers. However, alumina can remove part of this residual absorption, but with a poor yield. It should be observed also that purification of irradiated PF 5060 is limited at a value of ca. 2 absorbance units; it can correspond to the content of similar radiation induced molecules. PP1, which contains a branched molecule, appears to be less susceptible to form the above mentioned molecules during its radiolysis. A slight decrease in the maxim at ca. 200 nm was observed when the irradiated fluid (e.g. PF 5060-28) was treated by water (Fig. A14.18). This change could be the result of water solubilization or hydrolysis of some species such as fluorinated acids, fluoride salts or carbonyl fluorides respectively.

- 88 -

0.3

0.2

0.1 2 Absorbance (abs. units) 4 7 8 9 3 0 1 5 6 190 200 210 220 230 240 250

Wavelength (nm)

Fig. A14.2 - The effect of various activated carbon types on the optical absorption of PP1-28 (static experiments; stirring time 10 minutes): 1 - reference air; 2 - PP1-28; 3 - PP1 as received; 4 - Fluka 29204; 5 - Fluka 39388; 6 - Fluka 05113; 7- vegetal charcoal Prolabo; 8-Fluka 96831; 9-Riedel de Haen.

3

2

3 45 1 6 7 Absorbance (abs. units) 8 9 12 0 200 220 240 260 280 300 Wavelength (nm)

Fig. A14.3 - The effect of various activated carbon types on the optical absorption of PF 5060-28: 1-ref air; 2 - PF 5060 as received; 3 - PF 5060-28; 4 - Fluka 96831; 5 - Fluka 39388; 6 -Fluka 05113; 7 - vegetal charcoal Prolabo; 8 - Fluka 29204; 9 - Riedel de Haen.

- 89 -

2

3 4 1 5 8

Absorbance (abs. units) 6 7 2 1 9 0 190 200 210 220 230 240 250 Wavelength (nm)

Fig. A14.4 - The effect of various activated carbon types on the optical absorption of purified PF 5060–28 (static experiments; stirring time 10 minutes): 1 - ref air; 2 - PF 5060 as recd; 3 - PF 5060-28; 4 - Fluka 96831;5 - Fluka 29204; 6 - Fluka 39988; 7 - Fluka 05113; 8- vegetal charcoal Prolabo; 9 - Riedel Haen.

4

3

2 3 4 5

Absorbance (abs. units) 1 6 1 2 0 190 200 210 220 230 240 250

Wavelength (nm) Fig. A14.5 - The effect of KOH impregnated active carbon on the UV optical absorption of PF 5060-28: 1-.ref air; 2 - PF 5060 as received; 3 - PF 5060-28 (untreated); 4 - Fluka 29238; 5 - Fluka 29238 + Fluka 29204; 6 - Fluka 29238 + Fluka 99831.

- 90 -

0.3

0.2

0.1 7 6

Absorbance (abs. units) 5 4 3 8 0 1 2 200 220 240 260 280 300 Wavenumber (nm) Fig. 14.6 - The effect of various types of purifiers on the optical absorption of PP1-28: 1 - reference air; 2 - PP1 as received; 3 - PP1-28; 4 - Alumina for chromatography; 5 - Alumina pellets for drying; 6 - Silica for chromatography; 7 - Molecular sieves 13x; 8 - Fluka 39988.

4

3 3

2 4 5 6 7

Asborbance (abs. units) 1

1 2 0 200 220 240 260 280 300 Wavelength (nm) Fig. A14.7 - The effect of various types of purifiers on the optical absorption of PF 5060-28: 1 - ref air; 2 - PF 5060; 3 - PF 5060-28; 4 - Alumina drier; 5 - Alumina for chromatography; 6 - Silica for chromatography; 7 - Molecular sieves.

- 91 -

4

3

2 3

4

Absorbance (abs. units) 1 5 6 1 2 0 200 220 240 260 280 300

Wavelength (nm) Fig. A14.8 - Effect of the repeated alumina drier treatments on the optical absorption of PF 5060-28: 1 - reference air; 2 - PF 5060; 3 - PF 5060 - 28; 4 - Alumina 10'; 5 - Alumina 3x10'; 6 - Alumina 6x10'.

3

2 3 4 5 6 1 7 8 Absorbance (abs. units) 9

1 2 0 200 220 240 260 280 300 Wavelength (nm) Fig. A14.9 - Effect of combined alumina drier (6 x 10') and various other purifiers on the on the optical absorption of PF 5060-28: 1 - reference air; 2 - PF 5060 as received; 3 - PF 5060-28; 4 - alumina drier (6x10'); 5 - alumina drier (6x10') + Fluka 29204 + Fluka 28238; 6 - alumina drier (6x10') + Silica drier; 7 - alumina drier (6x10') + molecular sieves; 8 - alumina drier (6x10') + alumina drier used for purification and then thermally treated at 150 °C, 2.5h; 9 - alumina drier (6x10') + KMnO4 + vegetal charcoal Prolabo.

- 92 -

4

3

2 5 3 6 7

Absorbance (abs. units) 1 4 8 2 1 0 200 220 240 260 Wavelength (nm) Fig. A14.10 - Effect of combined alumina drier and vegetal charcoal on UV optical absorption of PF 28: 1 - reference air; 2 - PF 5060 as received; 3 - PF 5060 - 28; 4 - PF 5060 - 28 + alumina drier (10'); 5 - similar to (4) + vegetal charcoal Prolabo (10'); 6 - similar to (4) + vegetal charcoal Prolabo (2x10'); 7 - similar to (4) + vegetal charcoal Prolabo (3x10'); 8 - similar to (4) + vegetal charcoal Prolabo (4x10').

2

2 1.5 5 4 6 7 1 3

0.5 Absorbance (abs. units)

0 1

190 200 210 220 230 240 250

Wavelength (nm)

Fig. A14.11 - The effect of various types of purifiers on the optical absorption of purified PF 5060-28: 1 - reference air; 2 - PF 5060-28 untreated; 3 - Alumina for chromatography; 4 - Silicagel for chromatography; 5 - Molecular sieves 13x; 6 - Alumina pellets for drying; 7 - Fluka 29204.

- 93 -

Fig. A14.12 - Alumina pellets immersed in aqueous solution of methylene-blue: left - new, unused pellet; center – after use pellet with an yellow layer on the surface; right – after use pellet, having a part of the layer removed after immersion in methylene –blue: the dye penetration is observed only in the upper part of the pellet, from where the layer was removed.

0.8

0.6

0.4

0.2 5

Absorbance (abs. units) 3 2 4 7 6 0 1 200 220 240 260 280 300 Wavelength (nm) Fig. A14.13 - The effect of distillation and of other treatments on the UV optical adsorption of PP1-28: 1 - reference air; 2 - PP1 as received; 3 - PP1-28; 4 - distilled PP1-28, the light fraction; 5 - distilled PP1-28, the main fraction; 6 - PP1-28, the main fraction; 7 - PP1-28, the main fraction + Fluka 29238 and Fluka 29204.

- 94 -

3

2

6

1 4 3 Absorbance (abs. units) 5 7 8 1 2 0 200 300 400 Wavelength (nm)

Fig. A14.14 - The effect of distillation and of other treatments on the UV optical adsorption of PF 5060-28: 1 - reference air; 2 - PF 5060 as received; 3 - PF 5060-28; 4 - distilled PF 5060-28 - the light fraction; 5 - distilled PF 5060-28, the main fraction; 6 - distilled PF 5060-28, the heavy fraction; 7 - distilled PF 5060-28, the main fraction + Fluka 29238 and Fluka 29204; 8 - distilled PF 5060-28, the main fraction + (Fluka 29238 and Fluka 29204) + alumina drier.

1.6

1.2

0.8

3 0.4 Absorbance (abs. units) 4 2 0 1 200 220 240 260 280 300

Wavelength (nm) Fig. A14.15 - The UV optical absorbance of irradiated DL and of the its re-dissolved residue: 1 - reference air; 2 - DL as received; 3 - DL 28; 4 - residue of DL 28, re-dissolved in DL as received.

- 95 -

4

5 3

2 2

Absorbance (a.u.) Absorbance 4 1 3

0 1 200 250 300 350 Wavelength (nm)

Fig. A14.16 - Effect of distillation on the UV optical absorption of PF 5060-28: 1 - reference PF 5060-28 as received; 2 – PF 5060-28; 3 - distilled PF 5060-28, the light fraction; 4 - distilled PF 5060-28, the main fraction; 5 - distilled PF 5060-28, the heavy fraction.

0.4

0.3

0.2 3 5 6 0.1

Absorbance (abs. units) 4 7 1 2 0

200 220 240 260 280 300

Wavelength (nm) Fig. A14.17 - Effect of distillation and of subsequent treatments on the UV optical absorption of DL 28: 1 - reference air; 2 - DL as received; 3 - DL-28; 4 - DL-28 distilled, the main fraction; 5 - DL - 28 distilled, the main fraction + Fluka 96831 (10'); 6 - DL - 28 distilled, the main fraction + Alumina drier (10'); 7 - DL - 28 distilled, the main fraction + Alumina drier (2x10').

- 96 -

4 2

3

3 2

1 Absorbance (abs. units) (abs. Absorbance

0 1 200 300 400

Wavelength (nm) Fig. A14.18 - The effect of water extraction on the optical absorption of PF 5060-28; 1 - reference air; 2 - PF 5060 - 28; 3 - PF 5060-28 after water extraction.

B. Purification tests in circulating (continuous) mode Based on the results of the static tests, a laboratory installation for continuous purification of the fluids was realized. The main element is the purifier cartridge. A standard composition consisting in 1/3 alumina for drying, 1/3 molecular sieves 13x and 1/3 activated carbon Fluka 96831 was used for packing the cartridge; this cartridge will be named below 2809 (15 cm length). A shorter version (9 cm) was used in some experiments; this cartridge was codified as 2809S. Occasionally full alumina cartridge was used in alternate experiments. Supplementary small cartridges packed by alumina or silica for chromatography or by molecular sieves were also used in some experiments. In the case of PP1-28, the purification effect is clearly observed by UV spectrophotometry. The optical absorption decreased as increased the circulation time. For PP1-56, no absorption was observed. This behavior can be explained by completely oxygen lack during irradiation. In the case of PP1-28, it should be noted the irradiation bottle was no gas tight. A residual UV optical absorbance, of around 2 absorption units, was observed in the case of irradiated PF 5060. No changes in the absorbance were observed after purification of both irradiated DL and purified PF 5060. The results are in concordance with those from static experiments presented above. GC-MSD and FT-IR results confirm that the fluids are roughly purified in spite of the observed residual absorbance; there are traces of low molecular weight substances as well as high molecular weight compounds (observed in GC-MSD and FT-IR) which can contain chemical groups with high molar absorption coefficients, such as double bonds. Similar residual absorbance was observed in the case of PP1-AH-28 and PP1-AH-56 samples as well as for PF 5060-AH-28 and PF 5060-56 ones; large amounts of deposits were also observed in these cases; the behavior can be related to water radicals interference. - 97 -

0.01

3 0.2 0 1 2 4 (a) 5 (b) -0.01 6 0.1 -0.02

-0.03

Absorbance (abs. units) 0 1 Absorbance (abs. units)

-0.04 200 220 240 260 280 300 200 220 240 260 280 300 Wavelength (nm) Wavelength (nm)

Fig. A14.19 - UV absorbance of PP1-28 fluid before and after purification: 1 - reference PP1 as received; 2 – PP1-28; 3-6 - PP1-28 purified on cartridge 2809 for various time periods: 3 – 15'; 4 – 30'; 5 – 45'; 6 – 75' (a) - General view of the spectra; (b) - Zoom on the absorbance between -0.04 to + 0.1 abs. units.

0.02

0.01 2

0 1

-0.01 3 -0.02 Absorbance (abs. units)

-0.03

200 300 400 500

Wavelength (nm) Fig. A14.20 - UV absorbance of PP1-56: 1 - reference PP1 as received; 2 – PP1-56; 3 - PP1-56 purified on cartridge 2809.

- 98 -

0 1 1.5 (a) (b) 3 -0.01 4 1 2

-0.02 Absorbance (abs. units) Absorbance (abs. units) (abs. Absorbance 0.5

3 1 4 -0.03 0 200 220 240 260 280 300 200 220 240 260 280 300 Wavelength (nm) Wavelength (nm) Fig. A14.21 - UV absorbance of PP1-A-28 fluid (containing air), before and after purification: 1- reference.PP1 (as received); 2 – PP1-A-28; 3, 4 - PP1-A-28 purified on cartridge 2809: 3 – 75'; 4 – 120'. (a) - General view of the spectra; (b) - Zoom on the absorbance between -0.04 to + 0.1 abs. units.

1.2 (a) 7 1 5 (b) 6 1 4 3

0.5 0.8 2 2 Absorbance (abs. units) Absorbance (abs. units) 0.6 0 1 190 192 194 196 198 200 220 240 260 280 300 Wavelength (nm) Wavelength (nm) Fig. A14.22 - UV absorbance of PP1-AH-28 fluid (containing air and water): 1 - reference PP1 as received; 2 – PP1-AH-28; 3-6 - PP1-AH-28 purified on cartridge 2809: 3 – 15 min; 4 – 30 min; 5 – 45 min; 6 – 60 min; 7 – 75 min. (a) - General view of the spectra; (b) - Zoom on the absorbance between -0.5 to + 1.3 abs. Units.

- 99 -

2 2 3 4 (b) (a) 5 6 7

1 1 2 Absorbance (abs. units) (abs. Absorbance Absorbance (abs. units) (abs. Absorbance 2

0 1 0 1 200 220 240 260 280 300 190 200 210 220

Wavelength (nm) Wavelength (nm) Fig. A14.23 - UV absorbance of PP1-AH-56 fluid containing air and water:1 - reference PP1 as received; 2- PP1-AH-56; 3-5- PP1-AH-56 purified on cartridge 2809: 3 – 30 min; 4 – 60 min; 5 – 90 min; 6, 7- PP1-AH-56 purified on 2809 cartridge (90 minutes) followed by SiO2 cartridge: 6 – 30 min; 7 – 60 min. (a) - General view of the spectra; (b) - Zoom on the wavelength region 190...220 nm.

7 7 (a) 2 (b) 2

6 2 6 3 5 2 1 4 1.5 5 Absorbance (abs.units) Absorbance

Absorbance (abs. units) 3 4

1 0 1 1 190 200 210 220 190 192 194 196 198 200 Wavelength (nm) Wavelength (nm) Fig. A14.24 - UV absorbance of DL-28 fluid: 1 - reference DL as received; 2 – DL-28; 3 - DL-28 purified 15 min by cartridge 2809 + 15 min Alumina; 4 - 30 min cartridge 2809 + 30 min Alumina; 5 - same as (4) + Alumina drier (stirred, 2x10’); 6 – same as (4) + Fluka 96831 (2x10’); 7 - same as (4) + 10min Fluka 29238 + 10min Prolabo.

- 100 -

4

3

2 5

1 Absorbance (abs. units) 2

3 4 0 1 200 250 300 350 Wavelength (nm)

Fig. A14.25 - Effect of distillation on the UV optical absorption of DL 28: 1 - reference DL as received; 2 – DL-28; DL-28 purified 30 min. cart. 2809 + 30 min Alumina drier + distillation: 3 - light fraction; 4 - main fraction + Fluka 96831 (stirred, 10’); 5 – heavy fraction.

1

0.8 3

0.6 2 0.4

0.2 Absorbance (abs. units)

0 1

190 200 210 220 230 240 250 Wavelength (nm) Fig. A14.26 - Effect of purification on the UV optical absorption of DL 56: 1 - reference DL as received; 2 – DL-56; 3 – 60 min cartridge 2809.

- 101 -

3 2

2 3

1 4 Absorbance (abs. units) 5

0 1 200 220 240 260 280 300

Wavelength (nm) Fig. A14.27 - Effect of purification by activated vegetal charcoal (Prolabo) on the UV optical absorption of PF 5060: 1 - reference PF 5060 as received; 2 – PF 5060-28; 3 - PF 5060-28 + Prolabo (30’); 4 – PF 5060-28 + Prolabo (60’).

3 2

2

1 Absorbance (abs. units) 3 4

0 1 200 220 240 260 280 300

Wavelength (nm) Fig. A14.28 - Effect of purification by activated carbon (Fluka 96831) on the UV optical absorption of PF 5060: 1 - reference PF 5060 as received; 2 – PF 5060-28; 3, 4 - PF 5060-28 + Fluka 96831: 3 – 30 min; 4 – 60 min.

- 102 -

3 2

2

3 1 Absorbance (abs. units)

4 0 1 200 220 240 260 280 300

Wavelength (nm)

Fig. A14.29 - Effect of purification by activated carbon (Fluka 96831 + Fluka 29238) on the UV optical absorption of PF 5060: 1 - reference PF 5060 as received; 2 – PF5060-28; 3, 4 - PF 5060-28 + Fluka 96831 + Fluka 29238: 3 - 30 min.; 4 - 385 min.

2 3

3 2 5

6 1 Absorbance (abs. units)

4 0 1 200 220 240 260 280 300

Wavelength (nm)

Fig. A14.30 - Effect of purification by alumina drier (Fluka 06400) on the UV optical absorption of PF 5060: 1 - reference PF 5060 as received; 2 – PF5060-28; 3-6 - PF 5060-28 + alumina : 3 – 30 min; 4 – 40 min; 5 – 60 min; 6 – 210 min.

- 103 -

4 2 3

2 3

4 1 5 Absorbance (abs. units) 6 7 0 1 200 250 300 350 Wavelength (nm) Fig. A14.31 - Effect of continuous purification (cartridge 2809) on the UV optical absorbance of PF 5060-56: 1 - reference PF 5060 as received; 2 – PF 5060-56; 3 - 30’ circulation; 4 – 60’ circulation; 5 – 90’ circulation;6 - 90’ circulation + 30’ SiO2 cartridge; 7 - 90’ circulation + 60’ SiO2 cartridge.

4

3

2 3 2 4 5 6

Absorbance (abs. units) 1 7

0 1 200 250 300 350

Wavelength (nm) Fig. A14.32 - Effect of continuous purification (cartridge 2809) and subsequent distillation on the UV optical absorbance of PF 5060-56: 1- reference PF 5060 as received; 2 – PF 5060-56; 3 - PF 5060 purified 2809S (10’); 4-6 - PF 5060 purified 2809S, distilled: 4 – heavy fraction; 5 – main fraction; 6 - light fraction; 7 - same as (5) + SiO2 drier (stirring 10’).

- 104 -

2

1 2 3 4 5 Absorbance (abs. units)

0 1 200 220 240 260 280 300 Wavelength (nm) Fig. A14.33 - Effect of continuous purification (cartridge 2809) on the UV optical absorbance of purified PF 5060-28: 1 - reference purified 5060; 2 - purified 5060-28; 3 - 5 - purified 5060-28: 3 - 90'; 4 - 60'; 5 – 30'.

3

2 2

3 1 4 5 Absorbance (abs. units) 67

0 1 200 220 240 260 280 300

Wavelength (nm) Fig. A14.34 - Effect of continuous purification (cartridge 2809) on the UV optical absorbance of purified PF 5060-56: 1 - reference purified 5060; 2 – purified 5060-56; 3-5 - purified PF 5060-56 subsequently purified (post-irradiation): 3 - 30’; 4 - 60’; 5 – 90’; 6 - same as (5) + 30’ on SiO2 (for chromatography) cartridge; same as (5) + 60’ on SiO2 (for chromatography) cartridge.

- 105 -

ANNEX 15 - FT-IR spectra of irradiated and of purified fluids

0.01

0.005

2 3 0 1

-0.005 Absorbance (abs. units)

-0.01 2000 1900 1800 1700 -1 Wavenumber (cm ) Fig. A15.1 - FT-IR spectra of the PP1-28 before and after purification (45' by cartridge 2809 - see Annex 14): 1 - reference PP1 as received; 2 - PP1-28; 3 - purified PP1-28.

0.2

0.15

0.1 1890 1308 1875

0.05 1938 1783 1798 1774

3 2 1820

Absorbance (abs. units) 0 1 -0.05 2000 1900 1800 1700 -1 Wavenumber (cm ) Fig. A15.2 - FT-IR spectra of the PP1-A-28 before and after water extraction: 1 - reference PP1 as received; 2 - PP1-A-28; 3 - PP1-A-28, water extracted. The removed bands are related to CF2O and R-CFO compounds.

- 106 -

0.05 0.2

(a) (b) 0.15 1890 3619 3566

3124 2954 0.1 2

0 1308 1875 1 3

0.05 1938 1783 1798 1774

3 2 1820

Absorbance (abs. units) Absorbance (abs. units) 0 1 -0.05 -0.05 3800 3600 3400 3200 3000 2800 2000 1900 1800 1700 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.3 - FT-IR spectra of the PP1-A-28 before and after purification: 1 - reference PP1 as received; 2 - PP1-A-28; 3 - PP1-A-28, purified, cartridge 2809 (120'). (a) - the region of 3800 - 2700 cm-1; (b) the region of 2000 - 1700 cm-1. The bands related to the oxidation compounds (3619 cm-1, -1 -1 3566 cm , 3124 cm ) disappeared, as well as those related to CF2O and R-CFO; the band at 2954 cm-1 disappeared as well (it can be due to H atoms from water traces).

0.03 0.03

(a) (b)

0.02 0.02 1873 1888 3618 0.01 0.01 1773 1816 1801 3562

2993 2 3142 1751 1733 1716

2 1918 1964 0 Absorbance (abs. units) Absorbance (abs. units) 0 1 1 4 3 4 3 -0.01 -0.01 3500 3000 2500 2000 1900 1800 1700 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.4 - FT-IR spectra of PP1-AH-28 before and after purification: 1 - reference PP1 as received; 2 - PP1-AH-28; 3 - PP1-AH-28 purified 75' by 2809S cartridge; 4 - same as (3) + 45' alumina cartridge (a) - region of 3700 - 2500 cm-1; (b) - region of 2000 - 1700 cm-1. Purification removed most of the radiation induced species; the purified fluids present a weak residual IR absorbance in both the regions related to the observed UV optical absorbance; the IR absorbance values are however small and the fluid can be considered to be purified, as confirmed by the GC-MSD analyses.

- 107 -

0.02

0.04 1873 1888

0.01 3618

3562 0.02 2 1796 1773 1780 2989 3113 1817 2940 1846 2866 1830 1915

2 1753 1734 1717 3 3 0 4 0 1 Absorbance (abs. units) Absorbance (abs. units) 1 4

-0.01 -0.02 3600 3400 3200 3000 2800 2000 1900 1800 1700

-1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.5 - FT-IR spectra of PP1-AH-56 before and after purification: 1 - reference PP1 as received; 2 - PP1-AH-56; 3 - PP1-AH-56 water extracted; 4 - PP1-AH-28 purified 90' by 2809 cartridge + 60' -1 -1 SiO2 cartridge (a) - region of 3700 - 2500 cm ; (b) - region of 2000 - 1700 cm . Purification removed most of the radiation induced species; the purified fluid presents a weak residual IR absorbance in both regions related to the observed UV one; the IR absorbance values are however small and the fluid can be considered to be purified, as confirmed by the GC-MSD analyses; water treatment removed a part of the absorption at 1888 cm-1 and 1873 cm-1 (hydrolysable compounds - e.g. R-CFO or perfluorinated alkenes) as well as the broad peak at ca. 3100 cm-1 (fluoroalcohols or fluoroacids).

0.01 0.01 (b) (a) 1783 1942 2937 1728 1821 1840 2863 1879 3562 2972 3120 0 0 1 2 4 3 1 2 3 4 Absorbance (abs. units) Absorbance (abs. units)

-0.01 -0.01 3600 3400 3200 3000 2800 2000 1900 1800 1700 1600 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.6 - FT-IR spectra of DL-28: 1 - reference DL; 2 - DL-28; 3 - DL-28, water extracted; 4 - DL-28, purified on the alumina drier cartridge (30'). (a) - the region of 3700 - 2700 cm-1, (b) the region of 2000 – -1 1700 cm .The weak bands attributable to CF2O and R-CFO were removed by purification, as well as the bands at 3566 cm-1 and 3120 cm-1 (fluorinated peroxides and alcohols or acids); traces H- containing molecules, resulted from the water traces interference are also observed; these traces were removed by the purifier system; the spectrum of the purified is quite similar to the initial one, hence the fluid can be considered to be purified.

- 108 -

0.004 (a) 0.04 (b)(a)

0.002 0.02 3566 2937 2972 2863 3120 1877 1817 0 1 0 3 2 2 3 4 4 1 -0.002 -0.02 Absorbance (abs. units) Absorbance (abs. units)

-0.004 -0.04

3600 3400 3200 3000 2800 2000 1900 1800 1700

-1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.7 - FT-IR spectra of DL-56: 1 - reference DL; 2 - DL-56; 3 - DL-56, water extracted; 4 - DL-56, purified 60' on the cartridge 2809. (a) - the region of 3700 - 2700 cm-1, (b) the region of 2000 - 1700 cm-1. The -1 weak band (1877 cm ) attributable to CF2O and R-CFO was removed by purification, as well as the bands at 3566 cm-1 and 3120 cm-1 (fluorinated peroxides and alcohols or acids); traces of non- removable H-containing molecules (grafted on large fluorocarbon structures), resulted from the water traces interference are also observed; the spectrum of the purified is quite similar to the initial one, hence the fluid can be considered as purified.

0.004 (a)(a) 0.04 (b)(a)

0.002 0.02 3566 2937 2972 2863 3120 1877 1817 0 1 0 3 2 2 3 4 4 1 -0.002 -0.02 Absorbance (abs. units) Absorbance (abs. units)

-0.004 -0.04

3600 3400 3200 3000 2800 2000 1900 1800 1700

Wavenumber (cm-1) Wavenumber (cm-1) Fig. A15.8 - FT-IR spectra of purified PF5060-28: 1 - reference purified PF 5060 (unirradiated); 2 – purified PF 5060-28; 3 - purified PF 5060-28, extracted by KOH solution; 4 - purified PF 5060, water extracted; 4 -purified PF 5060-28, purified post-irradiation on the cartridge. (a)-region of 3700 – 2700 cm-1; (b)-region of 2000 - 1700 cm-1. Traces of H and O containing compounds (fluorinated peroxides, acids alcohols) as well as CF2O and R-CFO are induced by irradiation; most of these compounds are removed; the spectrum of the purified fluid is very similar to that of the initial, unirradiated one.

- 109 -

0.005 0.01 1944

0.004 1784 2938 1726 2968 0.003 4 2 1885 3 1840 1930

0.002 2865 0 1 3041 3 3132

3480 3440 2 0.001 3272 3197 Absorbance (abs. units) 4 Absorbance (abs. units) 0 1

-0.001 -0.01 3600 3400 3200 3000 2800 2000 1900 1800 1700 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.9 - FT-IR spectra of purified PF5060-56: 1 - reference purified PF 5060; 2 - purified PF 5060-56; 3 - purified PF 5060-56, water extracted; 4 -purified PF 5060-56, purified post-irradiation 90' on the 2809 cartridge. (a)-region of 3600 - 2700 cm-1; (b)-region of 2000 - 1700 cm-1. Traces of various impurities (fluorinated alcohols, peroxides and acids as well as to H substituted perfluorocarbons) are observed; the band at ca. 3100 cm-1 was removed, but there is another one at 3041 cm-1 which is partially removed (it can be due to H substituted perfluorocarbons resulted from the water traces interference). Note that all observed impurities are in negligible concentrations (see the absorbance scale).

1790

0.04 1836

2 1759 1813 1734

0.02 1720 1701 3 1686 1653 1867

Absorbance (abs. units) (abs. Absorbance 4 0 1

2000 1900 1800 1700 1600

-1 Wavenumber (cm ) Fig. A15.10 - FT-IR spectra in the 2000- 1600 cm-1 region of PF 5060-28 before and after water extraction or purification: 1 - reference PF 5060 as received; 2 - PF 5060-28; 3 - PF 5060-28, water extracted; 4 - PF 5060-28 purified 320' by 2809 cartridge. Similar peaks, but more intense bands than in other cases are observed, especially in the region 2000 - 1600 cm-1; however, no bands at 1900 cm-1 (either COF2 doesn't result or it is consumed by other subsequent reactions). The bands at 1790 and 1759 cm-1 can be related to hydrolysable perfluoralkenes, such as perfluoroisobutylene or to a hydrolysable or soluble carbonyl compound (ketone, RCOF or fluorinated acid). Purification is efficient, most of the compounds responsible for the observed IR bands were removed; some negligible traces of impurities still remain after the purification treatment.

- 110 -

0.06 3130 3007 3620 3560 2860 2 0.04 1790 0 1836

3 1 1759 4 5 1813

6 1734

0.02 1720 1672 2 1701 1867 -0.05 1653 0 1 Absorbance (abs. units) Absorbance (abs. units) 3 4 5 6 -0.1 -0.02 3600 3400 3200 3000 2800 2000 1900 1800 1700 1600 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.11 - FT-IR spectra of PF 5060-28 before and after purification by various purifying laboratory prepared cartridges: 1 - reference PF 5060 as received; 2 - PF 5060-28; 3 - alumina drier cartridge (60'); 4 - molecular sieves (90'); 5 - vegetal charcoal (Prolabo) (90'); activated carbon Fluka 96 831 (60'). (b). (a)-region 3700 - 2700 cm-1; (b)-region 2000 - 1600 cm-1. Purification results in a significant decrease of all the absorption bands; weak bands corresponding to traces of double bond molecules still remained after purification; Fluka 96831 appears slightly more efficient than other purifiers.

0.02 1790 1730 1720

0.01 2 1671 1747 1699 1684 1653 1871

1844 3 1826 1885

1940 4 Absorbance (abs. units) 0 1

2000 1900 1800 1700 1600

-1 Wavenumber (cm ) Fig. A15.12 - FT-IR spectra in the 2000- 1600 cm-1 region of PF 5060-56 before and after water extraction or purification: 1 - reference PF 5060 as received; 2 - PF 5060-56; 3 - PF 5060-56, water extracted; 4 - PF 5060-56 purified 90' by 2809 cartridge. Similar bands, as in PP-28, but less intense because the lack of air; no bands at 1900 cm-1. The bands at 1790 and 1759 cm-1 can be related to hydrolysable perfluoralkenes, such as perfluoroisobutylene or to a hydrolysable or soluble carbonyl compound (ketone, RCOF or fluorinated acid). Purification process is efficient, most of the compounds responsible for the observed IR bands were removed; only negligible traces of impurities still remain after the purification treatment.

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0.06 0.08

2972 (b) (a) 1782

0.06 1794 0.04 2944 1840 1815 2877 0.04 1859

0.02 1885 3110 1749 1734 3565 0.02 4 3618 2 2 Absorbance (abs. units) Absorbance (abs. units) 3 0 1 1915 1 0 3

-0.02 -0.02 3600 3400 3200 3000 2800 2000 1900 1800 1700 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.13 - FT-IR spectra of PF 5060-A-28: 1 - reference PF 5060 as received; 2 - PF 5060-A-28; 3 - PF 5060-A-28 purified 90' on 2809 cartridge; 4 - PF 5060-A-28, water extracted (presented only in (b). (a)-region 3700 - 2700 cm-1; (b)-region 2000 - 1700 cm-1.

0.05 0.03 (a) (b) 0.04 1780 1790

0.02 1730 0.03 1842 2 1776

2 1730 0.02 1747 0.01 1827 1747 1944 3 1930 1827

0.01 1842 1911

1890 1870 3 4 Absorbance (abs. units) 0 1 Absorbance (abs. units) 0 1

-0.01 -0.01 2000 1900 1800 1700 2000 1900 1800 1700 -1 -1 Wavenumber (cm ) Wavenumber (cm ) Fig. A15.14 - FT-IR spectra in the 2000 - 1700 cm-1region of PF 5060-AH-28 and PF 5060-AH-56. Weak bands at -1 -1 1944 cm and 1930 cm indicate the presence of CF2O traces in PF 5060-AH-28. No similar bands were observed in PF 5060-AH-56. A broad band with maxim at 1780 cm-1 is observed in PF 5060- AH-56; disappearing after water treatment, it can be assigned to R-CFO compounds.

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ANNEX 16 - Thermal behavior of the radiation induced pre-polymer in PF-5060-28 fluid

Table A16.1 - Residue (of PF 5060-28) weight variation as a function of the heating time

lost weight Heating time Temperature sample weight (Δm/m )·100 (min.) (°C) (g) 0 (%) 0 25 0.0212 0 15 50 0.0205 - 3.30 30 60 0.0191 - 9.91 45 70 0.0177 - 16.51 60 80 0.0163 - 23.11 75 90 0.0144 - 32.08 90 100 0.0118 - 44.34 105 110 0.0096 - 54.72 120 120 0.0072 - 66.04 135 130 0.0055 - 74.06 150 140 0.0040 - 81.13 165 150 0.0030 - 85.85 180 160 0.0024 - 88.68 195 170 0.0015 - 92.92 210 180 0.0015 - 92.92 225 190 0.0014 - 93.94 240 200 0.0013 - 93.87

-100 0.02 -80 0.016 -60 0.012 -40 Weight lost (%)

Polymer weight (g) 0.008

-20 0.004

0 50 100 150 200 o Temperature ( C) Fig. A16.1 - Residue weight and weight lost of the polymer as a function of temperature for PF 5060-28 sample