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
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.