Primary radical termination in methyl methacrylate polymerization

Abstract The kinetics of polymerization of methyl methacrylate in benzene solution at 60°C., initiated by 2,2′‐azobisisobutyronitrile (AIBN), were studied for monomer concentrations of 0.03–1M. The observed deviations in polymerization rate from the rates predicted by simple theory are discussed in terms of the occurrence of primary radical termination reactions. The fraction of primary radicals terminating chains was obtained for various monomer and initiator concentrations, and the ratio of rate constants for chain initiation and chain termination by a primary radical was determined.