Copolymerization of methyl methacrylate and butyl acrylate in the presence of a chain transfer agent

Copolymerizations of methyl methacrylate (MMA) and butyl acrylate (BA) have been performed using different monomer feed compositions in the presence of the chain-transfer agent dodecanethiol (DDT) at 60°C in benzene solution. The average chain-transfer constants as a function of the monomer feed composition were determined by using the conventional Mayo method and by the chain length distribution (CLD) procedure. The average chain-transfer constants obtained from both methods are compared to model predictions based upon both the terminal and penultimate unit models of free-radical copolymerization, and they are in satisfactory agreement with each other.