Gamma irradiation of polymers of arly and alkary methacrylates and acrylates

Poly(benzyl methacrylate) and poly(phenyl methacrylate) appear to degrade exclusively on gamma irradiation; energies for main‐chain, carbon‐carbon bond breaking are 711 and 228 e.v., respectively, which indicates a strong protective effect of the benzene ring. Poly(phenyl acrylate) requires higher doses to cause gelation than do poly(benzyl acrylate) and poly(phenylethyl acrylate), the latter behaving similarly to poly(n‐alkyl acrylates). Absence of hydrogen on the carbon adjacent to the ester link appears to be required to affect the radiation behavior of polyacrylates.