Emulsion copolymerization of styrene and methyl methacrylate. II. Molecular weights

A mathematical model for the time evolution of both number-average molecular weight and weight-average molecular weight is described. The model results in a set of ordinary differential equations and its application is not limited by the maximum number of radicals per particle. The model was used to analyze the effect of the monomer molar ratio in the initial charge on the weight-average molecular weight during the emulsion copolymerization of styrene and methyl methacrylate in a batch reactor.