CHANGES IN THE SUPERMOLECULAR STRUCTURE OF SILOXANE BLOCK-COPOLYMERS UPON GAMMA-RADIOLYSIS

The effect of radiation on changes in the supermolecular structure of dimethylphenylsilsesquioxane block copolymers was studied. It was foun d that their spheroidal shape remained unchanged. However, at doses of similar to 1 MGy, the sizes of spheroids decreased, and the size dist ribution was affected. Electron-microscopic examination of gel fractio ns of the irradiated block copolymers revealed that large spherical-pa rticles were formed in addition to small spheroids. Dimethylcyclosilox anes, which are present in initial block copolymers, take part in the radiation-induced chemical transformations of the siloxane block copol ymers.