FREE-RADICALS FORMED UPON PHOTOLYSIS AND RADIOLYSIS OF POLYMERS .1. RADICALS IN GAMMA-IRRADIATED AND UV-IRRADIATED POLYETHYLENE

Citation
Si. Kuzina et Ai. Mikhailov, FREE-RADICALS FORMED UPON PHOTOLYSIS AND RADIOLYSIS OF POLYMERS .1. RADICALS IN GAMMA-IRRADIATED AND UV-IRRADIATED POLYETHYLENE, High energy chemistry, 31(4), 1997, pp. 239-243
Citations number
20
Categorie Soggetti
Chemistry Physical
Journal title
ISSN journal
00181439
Volume
31
Issue
4
Year of publication
1997
Pages
239 - 243
Database
ISI
SICI code
0018-1439(1997)31:4<239:FFUPAR>2.0.ZU;2-0
Abstract
A comparative ESR study of photolysis and radiolysis of polyethylene a t 77 K showed that the radical intermediates formed differ in nature. The ESR spectrum of polyethylene photoirradiated at 77 K exhibited eig ht hyperfine structure lines (Delta H = 1.8-2.2 mT) and was interprete d as the spectrum of the terminal allyl radical stabilized on photoind uced defects of the polymer chain. Photolytic degradation of an excite d carbonyl-containing fragment of the polyethylene macromolecule with formation of the terminal allyl radical and low-molecular-weight photo degradation products was represented in terms of the model of synchron ous multicenter transitions.