Premium
Photochemical reactions of polyene sequences produced during the degradation of poly(vinyl chloride)
Author(s) -
Owen Eryl D.,
Pasha Ishrat
Publication year - 1980
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.1980.070251026
Subject(s) - benzophenone , polyene , chemistry , photochemistry , tetrahydrofuran , hydrogen atom abstraction , radical , diradical , vinyl chloride , reactivity (psychology) , polymer chemistry , solvent , organic chemistry , singlet state , medicine , physics , alternative medicine , pathology , nuclear physics , copolymer , excited state , polymer
Photosensitized reactions of tetrahydrofuran (THF) and dichloromethane (DCM) solutions of polyene sequences introduced into poly(vinyl chloride) molecules by chemical degradation have been investigated. The distribution of polyenes produced following further thermal degradation in DCM were shifted toward longer sequences than were observed for the same reaction in THF. Benzophenone‐sensitized bleaching of the polyene absorption in aerated THF solutions was characterized by induction periods, but the presence of oxygen had little effect on the same reaction in DCM. The bleaching process seems to involve reaction of the polyenes with the tetrahydrofuranyl radical formed by abstraction of the α‐hydrogen from THF by triplet benzophenone. No induction periods were observed for benzoin‐sensitized reactions, but the rate of reaction was faster in DCM than in THF. The differences are discussed in terms of the difference in reactivity of the alkyl and alkoxy radicals.