Butyl acrylate/vinyl acetate miniemulsion polymerization:: A study on compartmentalization

A series of butyl acrylate/vinyl acetate miniemulsions were investigated. Two procedures were used to prepare the miniemulsions: one in which the monomers were mixed together, sonicated, and polymerized, and the other, in which the individual monomers were sonicated prior to mixing and then polymerized. Kinetic and final properties of the obtained polymers were compared. The two procedures offer interesting insights into monomer compartmentalization in miniemulsions. In most cases, there were no differences in monomer conversion, copolymer composition, particle size or average molecular weights between the two procedures. ATR-FTIR spectroscopy was used to assess possible monomer transfer. The spectra obtained from each polymerization procedure were compared and no evidence of compartmentalization was found. Both procedures yielded similar spectra indicating that monomer transfer between particles occurred. In addition, adhesive properties of the obtained latexes were investigated. Due to the fact that relatively large amounts of CTA were used, adhesive performance was poor.