Aqueous Polymerization of Methyl Methacrylate. IV

The aqueous polymerization of methyl methacrylate (MMA) initiated by the potassium bromate-thiomalic acid (TMA) redox system was investigated in the presence of atmospheric oxygen at 35 ± 0.2°C. As the monomer MMA concentration and initiator KBrOs concentration were increased, there was a corresponding increase in both the initial rate and limiting conversion. It was observed that with an increase in activator TMA concentration both the initial rate and the maximum conversion increased up to a certain limit. There was then a fall in initial rate and maximum conversion. The rate of polymerization is given by the relation where x = 1.06 and 0.06 for lower and higher initiator concentrations, respectively. The energy of activation (Ea) was calculated from an Arrhenius plot and found to be 57.98 kJ/mol (13.36 kcal/ mol) under the temperature range investigated (20–45°C).