Effect of Ionizing Radiation on a Series of Saturated Polyesters

Abstract

The effect of ionizing radiation on a series of saturated linear polyesters containing the repeating unit in which R₁ and R₂ are linear or branched alkylene groups, is reported. Cross-linking and scission were shown to be influenced greatly by the structural features of R₁ and R₂ and the intrinsic viscosities of the polymers. A dose-rate independence was observed for the polymers in vacuo, whereas in air, degradation was related to diffusion of the gas into the polymer. Amorphous polymers were shown to cross-link more readily than the crystalline and oriented polyesters; trapped radicals in the crystalline polymers cause delayed cross-linking when the polymers were subsequently heated.