Peculiarities of formation and reactions of macroradicals in γ-irradiated ethylene-acetylene copolymers

The radical products of y-radiolysis of the ethylene-acetylene copolymer were identified, and their radiation-chemical yields were estimated for irradiation at 77 and 293 K. It is suggested that the nonadditive effect in the formation of polyenyl radicals in the copolymer irradiated at 77 K is due to the positive hole migration along the polyethylene chain followed by deprotonation at the boundary between polyethylene and polyacetylene blocks. Radical site transfer resulting in the formation of polyenyl radicals was found to occur upon warming the irradiated samples to 220-353 K. The stability of macroradicals of various kinds within the temperature region of 293 to 353 K was estimated.