Aqueous polymerization of methyl methacrylate. III

The aqueous polymerization of methyl methacrylate (MMA) initiated by potassium persulfate (I)‐thiomalic acid (TMA) redox couple has been studied at 30 ± 0.2°C under nitrogen atmosphere. The rate of polymerization is given by up to 20.0 mmol/L TMA concentration, where x = 0.52 for the I concentration 0.6–10 mmol/L and x = 0.27 for higher I concentrations. The temperature had a marked effect on initial rate and maximum conversion. The overall energy of activation was found to be 11.79 kcal/mol (49.31 kJ/mol). Injection of more initiator (I) at intermediate stages enhanced both the initial rate and maximum conversion. Ag (I) and Fe (III) depressed initial rate as well as maximum conversion, while Cu (II) activated the polymerization. The effect of solvent was also studied.