Premium
Heat aging in fluoroelastomers
Author(s) -
Thomas D. K.
Publication year - 1964
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/app.1964.070080331
Subject(s) - polymer , diamine , materials science , relaxation (psychology) , copolymer , natural rubber , stress relaxation , polymer chemistry , compression set , composite material , psychology , social psychology , creep
Continuous and intermittent stress relaxation measurements have been made on a copolymer of vinylidene fluoride and hexafluoropropylene crosslinked with diamines or high energy radiation, and a study has been made of the effect of heat on the raw polymer. The results show that heat aging in diamine vulcanizates is the result of two simultaneous processes; one is a rapid oxidative reaction in and at the crosslinks resulting in the replacement of the primary crosslinks by a more thermally stable type, and the other is an oxidative reaction in the polymer main chain leading to a very slow breakdown of the rubber network. This second reaction is thought to be identical with that occurring in the unvulcanized polymer. The surprisingly poor resistance to compression set of diamine vulcanizates is consistent with the first process, and the good long‐term aging properties are a result of the second one.