Identification of free radicals produced by the radiolysis of poly(methyl methacrylate) and poly(methyl acrylate) at 77°K

The evolution of the ESR spectra of poly(methyl methacrylate) (PMM) and poly(methyl acrylate) (PMA) gamma irradiated at liquid nitrogen temperature has been studied as a function of temperature between 100°K and 320°K. In both cases, six radicals have been identified which are already present at 100°K. Some of these are a direct consequence of high energy irradiation while others are due to subsequent hydrogen transfer reactions. The results are discussed on the basis of a mechanism previously proposed for the radioysis of PMM.