Radiation graft copolymerization in aqueous dispersion

The rates of polymerization of monomers in rubber in aqueous dispersion are higher than in the corresponding bulk polymerizations. The higher rates, which are independent of latex concentration over the range of concentration studied, have been attributed to the ingress of free radicals from a certain volume of the aqueous phase surrounding each particle. The γ‐radiation‐initiated graft polymerization of styrene with rubber is similar to that with methyl methacrylate, though the fraction of grafted polymer is lower. In the photoinitiated systems, styrene behaves differently from methyl methacrylate in that the rate of polymerization diminishes at higher monomer concentrations.