Application of molecular characterization for polymers using thermal desorption/pyrolysis DART-MS Chikako Takei1, Kenichi Yoshizawa1, Derek Gonzales*2, Sayaka Nakamura3, Hiroaki Sato3 ; 1 BioChromato, Inc., 2 BioChromato USA, 3 National Institute of Advanced Industrial Science and Technology Introduction Results and Discussions For every fluorine polymer samples, oligomeric pyrolysis products could be successfully observed by TDP/DART-MS in negative ion mode. The KMD plot converted from each mass spectra showed that the oligomeric products contain CF units as a base unit. Fluorine polymers are utilized in the field of semiconductor technologies and automotive 2 products due to their excellent chemical durability and mechanical properties. Molecular C2F3O2 C F O C F O C8F17 16 31 2 characterization of fluorine polymers is important because they are often copolymerized or 3 6 PTFE C F O ~ PTFE ~ modified to achieve higher performance, but it has been quite cumbersome. Even by 8 15 2 Heated at 600℃ The KMD plot of the PTFE sample depicted mainly two horizontal lines pyrolysis (Py)-GC/MS, only monomer type can be barely determined. MALDI-MS is C2F5 C8F17 almost impossible to observe the mass spectra of fluorine polymers due to their CF2 reflecting a CF2 repeating unit. Interestingly, the products lined in the C16F31O2

nonpolarity. KMD lower mass region could be identified as oxygen containing products. This presentation demonstrates the molecular characterization of fluorine polymers using Such oxygen-containing products would be attributed to the chain a thermal desorption and pyrolysis (TDP)/DART-MS, which can rapidly detect both terminal containing polymerization initiators or chain transfer agents. thermally desorbed intact oligomers and oligomeric pyrolysis products of polymers. By 1) introducing Kendrick mass defect (KMD) analysis ,sequence analysis of fluorine Base unit; CF2 copolymers can also be performed. m/z 1) H.Sato, S.Nakamura, K.Teramoto, T.Sato; JASMS, 2014, 25(8), 1346-1355 C8F17 C2F3O2 C16F31O2 C3F5O2 PFA C8F15O2 Heated at 600℃ ~ PFA ~ Experimental CF2 C16F31O2 C2F5 Although the KMD plot of the PFA sample was similar to that of PTFE, Samples C8F17 mass spectral pattern of low molecular weight products would be a 4 kinds of fluorine polymer products(commercial products) C4F9

KMD clue to discriminate between PTFE and PFA. The KMD pattern with C5F9O2 ETFE almost no oxygen distribution suggested low contents of the perfluoro PFA ether unit. PTFE C2F5

Base unit; CF2 FKM m/z C H C12H12F11 2 4 C2H4 C2H4 C2F5 C F CF2 ETFE CF2 3 7 Heated at 430～450℃ ~ ETFE ~ n m The KMD plot of ETFE showed a parallelogram-like pattern reflecting n 415.08 CF and CH comonomer distribution. Short sequence of CF indicated R Rf: perfluoro alkane 2 2 2 f C4F7O2 KMD PTFE; PFA; Perfluoro alkoxyl alkane the ETFE sample would have high randomness. C12H12F11

n m C F ETFE; - copolymer 2 5 Base unit; CF2 m/z VDF PfMVE TFE PfMVE PfMVE C F O FKM n m l PfMVE 9 19 3 C11F23O4 Heated at 460～500℃ TFE ~ FKM ~ FKM; (Vinylidenefluoride-perfluoromethylvinylether-tetrafluoroethylene) terpolymer C6F13O2 C F O Higher molecular weight products such as PfMVE-TFE (m/z 284.99), 3 7 C F O 13 27 5 dimer of PfMVE (m/z 350.99) and trimer of PfMVE (m/z 516.98) could Analytical methods: TDP/DART-MS (Fig. 1)

KMD be detected. These products could not observe in the mass spectra Sample (ca. 0.2 mg) were used for measurement. C F O 5 11 obtained by Py-GC/MS. By using KMD analysis, the sequence C12F25O4 Mass Spec. : compact (Bruker) Inside 165.99Da Ion Source : DART®-SVP (IonSense) PfMVE distribution of comonomers and terminal structures were also Ionization gas : Helium 165.99Da characterized. Gas temperature : 400℃ MS C4F9O2 Base unit; CF2 TDP device : ionRocket (BioChromato) DART® Temperature : RT → 600℃ (100℃/min) m/z 600℃

300℃ samples Fig. 3 TDP/DART(-)-MS spectra of at each sample’s pyrolysis temperature and their KMD plots (Base unit; CF2) ℃ POT RT TDP device 0 1 4 7 min Conclusion TDP/DART-MS enables measurement of not only low molecular weight but also oligomeric pyrolysis products of fluorine polymers. Therefore, it give us valuable Fig.1 TDP/DART-MS system Fig. 2 Temperature program of TDP device clue to elucidate chemical structure of fluorine polymers (ex. chemical structural analysis of perfluoro alkane (Rf) of PFA, estimation of polymerization method by Kendrick Mass Defect(KMD) analysis was used a “Spectra Scope (BioChromato)” software. polymerization initiator and chain transfer agent and so on). Thus, it can contribute to further development of fluorine polymer analysis technology.