Abstract
New data referring to quantum efficiency of electronically excited macroradicals and radical anion reactions in various carbon- and heterochain polymers at temperatures below their glass transition or melting points are presented and discussed. The data on the mechanism of the photochemical reactions of peroxy radicals, the effect of various factors (photon energy, free volume, degree of crystallinity) on the direction and efficiency of reactions of electronically excited macroradicals are considered. The important role of photochemical chain reactions in photoageing is demonstrated. It is found that by varying photon energy, temperature, photolysis time and by taking advantage of the competition between thermal and photochemical reactions, it is possible to change the functional composition and molecular mass distribution of polymers in the desired direction.
References
Belevskii V N 1990Reactions of radical cations in condensed phase, D Sc dissertation, Moscow State University, Moscow (in Russian)
Bhattacharyya D and Willard J E 1982J. Phys. Chem. 86 962
Chettur G and Snelson A 1987J. Phys. Chem. 91 913
Gurman V S and Pergushov V I 1981Chem. Phys. 55 131
Korol’kova E M, Radzig V A and Mel’nikov M Ya 1991Khim. Fiz. (Sov. J. Chem. Phys.) 10 41 (in Russian)
Langhoff S R and Jaffe R L 1979J. Phys. Chem. 71 1475
Mel’nikov M Y 1987 InFizicheskaya khimiya. Sovremenniye problemy (Physical chemistry. Modern problems) (Moscow: Khimiya) pp. 48–88 (in Russian)
Mel’nikov M Ya and Seropegina E N 1989Radiat. Phys. Chem. 33 151
Mel’nikov M Ya and Smirnov V A 1994Fotokhimiya organicheskikh radikalov (Photochemistry of organic radicals) (Moscow: University Publishing House) p. 334
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mel’Nikov, M.Y., Pergushov, V.I. & Seropegina, E.N. Photoradical ageing of polymers. Proc. Indian Acad. Sci. (Chem. Sci.) 107, 841–849 (1995). https://doi.org/10.1007/BF02869976
Issue Date:
DOI: https://doi.org/10.1007/BF02869976