EFFECTS OF GAMMA-IRRADIATION ON METHACRYLONITRILE-STYRENE COPOLYMERS AT -196-DEGREES-C

The radiation chemistry of methacrylonitrile-styrene copolymers which were gamma-irradiated at -196 degrees C with different radiation doses has been investigated by ESR spectroscopy. The calculated G(R(.)) val ues show that the copolymers display significant radiation protection effects. The mechanism of these effects has been discussed. In additio n, annealing experiments for a copolymer sample show that there are di fferent stages of radical decay, which reflect the stabilities of diff erent kinds of radical species and the mobility of the chain segments in the copolymer.