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6251445 
Journal Article 
PHOTOAGEING OF POLYMERS STIMULATED BY FREE-RADICALS 
Melnikov, MY; Lipskerova, EM; Mikhailik, OM; Fock, NV 
1982 
2 
2 
133-150 
WOS:A1982NG86300005 
The kinetics and mechanisms of photochemical reactions of macroradicals in various polymers in the absence of oxygen were studied at low temperatures. Some methodological problems connected with the conducting of this research were studied. Results were obtained on absorption spectra of macroradicals formed in poly(methyl methacrylate), poly(vinyl acetate), polypropylene, poly(vinyl butyral), poly(vinylene carbonate) and poly(methylene oxide). The photochemical reactions of macroradicals in the polymers studied (polypropylene, polyisobutylene, poly(vinyl butyral), polyvinylpyrrolidone, poly(ethylene oxide), poly(methylene oxide), poly(vinylene carbonate), poly(methyl methacrylate), poly(vinyl acetate), polyurethanes) were found to destruct the functional groups in the side chains of polymers and in the main chains of polymers with 10−1–10−4 and 10−1–10−5 quantum yields, respectively. Photoradical chain reactions occurred in poly(methyl methacrylate), poly(vinyl acetate), poly(ethylene oxide), poly(vinyl butyral) and polyurethanes. The photochemical reactions of macroradicals together with their thermal reactions were found to have an important effect on the photoageing of polymers over a wide temperature range.