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The photo‐oxidation of poly(vinyl chloride) investigated by a stress relaxation technique
Author(s) -
Cox W. C.,
Crawford D. J.,
Peill P. L. D.
Publication year - 1970
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.1970.070140308
Subject(s) - vinyl chloride , activation energy , relaxation (psychology) , radical , stress relaxation , materials science , irradiation , hydrogen atom abstraction , kinetics , oxygen , ultraviolet , polymer chemistry , photochemistry , chemistry , composite material , organic chemistry , polymer , creep , psychology , social psychology , physics , optoelectronics , quantum mechanics , nuclear physics , copolymer
A stress relaxation technique was used to study the kinetics of the photo‐oxidation of plasticized poly(vinyl chloride) film. The effects of ultraviolet irradiation were characterized by the slope of a difference line between the stress relaxation curve of an irradiated test sample and that of a nonirradiated control. An activation energy of 12 kcal/‐mole was obtained for the rate‐controlling reaction, which was postulated to be hydrogen abstraction from the substrate by peroxy radicals. The rate of relaxation was dependent on the radiation energy, being greater at lower energies. It was also independent of oxygen pressure at “high” pressures and dependent at “low” pressure. The nature of the plasticizer and the presence of stabilizer and ultraviolet absorbers all affected the relaxation behavior.