Phase Transfer Catalysis: Polymerization Kinetics and Mechanism of Methyl Acrylate

Kinetics and mechanism of the free-radical polymerization of methyl acrylate (MA), using potassium peroxomonosulfate (PMS) as a water-soluble initiator in the presence of benzyltributylammonium chloride (BTBAC) as a phase-transfer catalyst (PTC), were studied. The polymerization reactions were carried out under inert and unstirred conditions at a constant temperature of 60 +/- 1 degrees C in ethyl acetate/water biphasic medium. The rate of polymerization (R-p) increased with an increase in the concentrations of MA, BTBAC and PMS. The order with respect to the monomer, initiator, and PTC was found to be 1.0, 0.5, and 0.5 respectively. Rp was independent of the ionic strength and pH of the medium. Based on the kinetic evidences a suitable mechanism is proposed.