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Studies on γradiation treatment of poly(tetrafluoroethylene) powder
Author(s) -
Lunkwitz K.,
Bürger W.,
Geibßler U.,
Petr A.,
Jehnichen D.
Publication year - 1996
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19960613)60:11<2017::aid-app27>3.0.co;2-5
Subject(s) - tetrafluoroethylene , crystallinity , irradiation , amorphous solid , materials science , chain scission , polymer , carboxylation , polymer chemistry , degradation (telecommunications) , polytetrafluoroethylene , chemical engineering , nuclear chemistry , chemistry , organic chemistry , composite material , copolymer , catalysis , telecommunications , physics , computer science , nuclear physics , engineering
γ‐Irradiation of poly(tetrafluoroethylene) (PTFE) in the presence of air results in degradation of polymer chains by insertion of oxygen. At first, in the low‐dose range below 400 kGy, a rise in crystallinity can be observed due to main chain scission in the amorphous part of the macromolecules. Dose increase up to approximately 1000 kGy causes progressive degradation of molecular weight as well as a growing degree of carboxylation of PTFE and increased concentration of trifluoromethyl groups in near‐surface regions. At constant irradiation temperature, the properties of irradiated PTFE hardly depend on dose rate and starting material. The degree of carboxylation of the irradiated unsintered PTFE is appreciably lower in comparison with electron‐irradiated PTFE under comparable conditions. © 1996 John Wiley & Sons, Inc.