The kinetics of the copolymerization of alpha-methyl styrene (AMS) and butyl acrylate (BA) have been studied for the first time, Reactivity ratios for the system have been assessed over a range of temperatures (60-140 degreesC). Copolymerization models that account for monomer depropagation have been considered in order to determine the importance of depropagation effects for the chosen set of reaction conditions. Full conversion range experiments have been carried out to assess the effects of feed composition, temperature and initiator concentration on polymerization kinetics.