Emulsion polymerization of vinyl acetate and styrene monomers in presence of polymeric surfactant

Polymeric surfactant was prepared from polyoxyethylene methylether (POE, 66 wt%) and styrene (St, 34 wt%) in the presence of benzoyl peroxide as initiator using a macroradical polymerization technique. Fourier Transform Infrared Spectroscopy (FTIR) and (HNMR)-H-1 were used to confirm the formation of graft copolymer. The cloud point for the obtained graft copolymer was found to be 75 degrees C. The stabilizing efficiency of this nonionic copolymer as surfactant was tested in the emulsion polymerization of vinyl acetate and styrene monomers in the presence of potassium persulfate (K2S2O8) as initiator. The rate of polymerization was found to be proportional to the 0.9th and 0.76th power of initiator concentrations, and to the 0.77th and 0.66th power of the surfactant concentrations for vinyl acetate and styrene monomers, respectively. The apparent activation energies were found to be 69.13 and 50.27 kJ/mol for emulsion polymerization of vinyl acetate and styrene, respectively.