Photochemical reactions of polyene sequences produced during the degradation of poly(vinyl chloride)

Autor: Ishrat Pasha, Eryl D. Owen
Rok vydání: 1980
Předmět:
Zdroj: Journal of Applied Polymer Science. 25:2417-2426
ISSN: 1097-4628
0021-8995
DOI: 10.1002/app.1980.070251026
Popis: 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.
Databáze: OpenAIRE