IAEA-TECDOC-1062 XA9949176 Stability and stabilization of polymers under irradiation Final report of a co-ordinated research project 1994-1997 INTERNATIONAL ATOMIC ENERGY AGENCY /A\ 30-10 The originating Section of this publication in the IAEA was: Industrial Application Chemistrd san y Section International Atomic Energy Agency Wagramer Strasse 5 0 10 x P.OBo . A-1400 Vienna, Austria The IAEA does not normally maintain stocks of reports in this series. However, copies of these reports on microfiche or in electronic form can be obtained from INIS Clearinghouse International Atomic Energy Agency Wagramer Strasse5 P.O. Box 100 A-1400 Vienna, Austria E-mail: CHOUSE® IAEA.ORG URL: http://www.iaea.org/programmes/inis/inis.htm Orders shoul accompaniee db prepaymeny db Austriaf o t n Schillings 100,- for fore e chequa th f IAEmth f m o o n n i i Ar e o microfich e service coupons orderee whicb y hdma separately fro INIe mth S Clearinghouse. STABILITY AND STABILIZATION OF POLYMERS UNDER IRRADIATION IAEA, VIENNA, 1999 IAEA-TECDOC-1062 ISSN 1011-4289 ©IAEA, 1999 Printed by the IAEA in Austria January 1999 FOREWORD Considerin beneficiae gth l use f higo s h energy radiatio healtn ni h carpolymed ean r processing industries, two major applications can be seen to be emerging and becoming well established. Thes sterilizatioe ar e f singlno e medicaeus l disposable modificatiod an s f o n polymer properties. Both involve extremely small chemical changes applieo t d macromolecules yet resulting in new systems with very considerable physical and biological advantages. The major challenge of every radiation processing application where macromolecule involvee s ar inhibitio e th s di f unwanteno d material property changes which often occur when material e irradiate ar so predict d an dt useful lifetimes. Stabilitd an y stabilization of polymers under irradiation environments thus has become a key issue in the extensive and still growing use of radiation processing in polymer processing and modification. Durin lase gth t decad numbeea meetingf ro s have been organized unde auspicee rth f so the IAEA in order to elaborate recent developments in the application of radiation chemistry in polymer based industries. The Co-ordinated Research Project (CRP) on Stability and Stabilization of Polymers under Irradiation was initiated in 1994 based on the recommendation of the final Research Co-ordination Meeting on Radiation Damage to Organic Materials in Nuclear Reactors and Radiation Environment (IAEA-TECDOC-351) and the Advisory Group meeting organized in Universite th 199 t a 1 Marylandf yo , United State Americaf so . establishes wa purpose P th r CR dfocusinf fo e eo Th attentioe gth technicaf no l experts on the complex task of establishing a better understanding and attacking problems of radiation degradation of polymers. The group interactions have been designed to achieve a synergistic interaction among the research groups for the purpose of identifying degradation problems, exchanging ideas and results on the solution of these problems. It was clearly pointed out during the active discussions that important new approaches are developing for the stabilizatio materialf no ionizino st g radiation Researce Th . h Co-ordinated Meetings (RCMs) hel providedP durinCR forue e gd th th exchangr mfo f researceo h ideas, which otherwiss ei not occurring very effectively in this field. The present publication includes the contributions presented at these meetings. Collectively, they describe the progress in understanding and controlling the radiation induced changes mosd an , t extensively degradation polymerin i , c materials hopes i t I . d tha t wili t l provid usefuea l overvie currenf wo t activitie futurf o d esan trend thin si s field wore d Th .k an efforts of all contributors and expert editing of this TECDOC by R. Clough is gratefully acknowledged. The IAEA officer responsible for this publication is O. Giiven of the Division Physicaf o Chemicad lan l Sciences. EDITORIAL NOTE In preparing this publication press,for IAEAthe staff of have pages madethe up from the original manuscripts as submitted by the authors The views expressed do not necessarily reflect those of the IAEA, the governments of the nominating Member States or the nominating organizations Throughout the text names of Member States are retained as they were when the text was compiled The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions delimitation ofthe or of their boundaries The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as endorsementan recommendationor partthe IAEA ofon the The authors are responsible for having obtained the necessary permission for the IAEA to reproduce, translate materialuse or from sources already protected copyrightsby CONTENTS Summary of the co-ordinated research project..................................................................;............. 1 Studies on radiation stability of polymers..................................................................................... 11 Jiazhen Sun, Xiaoguang Zhong Annealing phenomena in the radiation degradation of crosslinked polyolefins ...........................21 M. Celina, K.T. Gillen, R.L. Clough Selectivit radiation-inducef yo d processe hydrocarbonsn si , related polymers and organized polymer systems....................................................................41 V.I. Feldman, F.F. Sukhov, A.A. Zezin, A.Yii. Orlov Radiation stabilization effect ethylene-propylenn a n si e copolymen i d ran epoxy resin particulate composites........................................................................................... 65 S. Baccaro, B. Bianchilli, C. Casadio, G. Rinaldi Improvement of polymer stability by radiation grafting............................................................... 79 F. Ranogajec, M. Mlinac-Misak Results of radiation tests at cryogenic temperature on some selected organic material LHC...................................................................................e th r sfo 1 .9 M. Tavlet, SchonbacherH. Evaluation of stability of polymeric insulation materials in radiation fields and development of radiation stable PVC and polypropylene for medical devices........................ 97 M.E. Gonzdlez, A.S. Docters Change moleculan si r structur propertied ean irradiatef so d polymerf so different compositions — ESR and NMR study.................................................................... 111 T. Carswell-Pomerantz, Babanalbandi,A. Dong,L. D.J.T. Hill, M.C.S. Perera, P.J. Pomery, G. Saadat, A.K. Whittaker Development of formulations of polyethylene-based flame retardant, radiation resistant wires and radiation-compatible polypropylene......................................... 129 S. Ahmed, Zhou Ruimin List of Participants...................................................................................................................... 141 SUMMARY OF THE CO-ORDINATED RESEARCH PROJECT 1. BACKGROUND The contributions presented in this technical publication describe progress in understanding and controlling the degradation of polymeric materials induced by exposure to ionizing radiation. This subject widespreaf areo s ai d importanc industriao et radiatiof o e us lr nfo two classe applicationsf so processine th ) 1 : productiod gan polymerif no c material meany sb f so irradiation facilities, and 2) the use of polymeric materials in applications for which they must withstand irradiation throughout the course of their useful lifetimes. Due to the extensive and still-growing use of polymeric materials for technological application immensf so e varietyface th t d thaan ,t radiation-processin potentiae th s g ha pla o lt n ya expanding role hi polymer manufacturing (current uses include crosslinking, curing, sterilization, surface modification, lithography, etc.) abilite ,th inhibio yt t unwanted material property changes which often occur when materials are irradiated, and to predict useful lifetimes, remains a limiting factor in a number of existing radiation technologies. Additionally, the ability to control unwanted degradation wil necessare b l successfur yfo l implementatio f futureno , more advanced, radiation processing schemes. The phenomena involved in radiation-degradation are exceedingly complex. In some instances, suitable stabilization technology is yet to be developed. In other cases, a functional stabilization schem fundamentas existit y t ema bu , l basi details wels it sa s solele e a l sar th n yi morr o e hande on privat f so e firms keeo informatioe pwh th , n proprietary. Despit neede eth f so both developin developed gan d nation radiatior sfo n stabilization methodologies, there exist only fragmented and widely scattered research efforts in this area, and the results are often not well communicated. Similarly case th materialf eo n i , s neede constructioe th n di radiation-relatef no d facilities (nuclear power plants, particle-physics experimental facilities, radiation processing plants, nuclear waste storage technologies, space vehicles, future fusion reactors, etc.), the ability to develop radiation-resistant materials wily capabilitke l continua e f widespreab o y o t e d importance. This co-ordinated research project was established for the purpose of focusing