The mechanism of radiation damage to elastomers. I. Chain scission and antirad action

Abstract The effect of antirads on the gamma radiation yields of scission in black loaded natural rubber stocks has been studied. The yield of chain scission has been measured by stress relaxation methods. The antirads were found to decrease the rate of chain scission, both in air and under nitrogen, with the antirad effectiveness being greater in the former case. The presence of oxygen accelerated the radiation induced chain scission. These results may be explained if it is assumed that (1) RO2 · radicals lead to chain scission more readily than do R · radicals, and (2) RO2 · radicals react with antirads leading to stabilized products more readily than do R · radicals.