Some comparative aspects of particle formation and rate of reaction in emulsion polymerization of vinyl acetate and butyl acrylate

Abstract

AbstractThe comparative study of monomers, in terms of particle formation and rate of polymerization, facilitates the interpretation of the results from the corresponding copolymerization runs and can be considered as a preliminary step toward formulation of copolymerization reactions. Batch emulsion homopolymerization of vinyl acetate (VA) and butyl acrylate (BA), as model monomers with a wide water solubility disparity, were carried out to investigate the effects of variations in the monomer concentration, electrolyte concentration, reaction volume, and surfactant type on the kinetics of polymerization. With sodium lauryl sulfate as surfactant, VA emulsion polymerization produced more particles than BA at a lower monomer concentration, but fewer particles at a higher monomer concentration. At a lower VA concentration, a depressed growth for newly formed particles during interval III contributed to the formation of a large number of particles. The application of aerosol MA and OT surfactants improved the stability of polyvinyl acetate (PVA) particles so that a larger number of polymer particles was obtained for VA, in comparison with BA. BA emulsion polymerization showed little sensitivity to electrolyte concentrations and reaction volumes within the range studied. The colloidal stability of PVA particles was found to be quite sensitive toward the aforementioned variables. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010