Study on concentrated emulsion polymerization of methyl methacrylate/butyl acrylate initiated by redox system

Stable concentrated emulsions of methyl methacrylate/butyl acrylate(MMA/BA) were prepared by using sodium dodecyl sulfate(SDS) and cetyl alcohol(CA) as the compound surfactant, polyvinyl alcohol(PVA) as the major reinforcer of liquid film. The concentrated emulsions polymerization was carried out with benzoyl peroxide/N, N'-dimethyl phenylamine (BPO/DMA) as redox initiators at low temperature. When the whole reaction time lasts about 300 min, as is expected, the conversion can be as large as over 96%, and which is higher in comparison with that in concentrated emulsion polymerization initiated by heat initiators. The kinetic behaviors of concentrated emulsion polymerization and time-conversion curves in constant rate range (conversions from 20% to 70%) were investigated. The size and distribution of particle diameter and morphology of latex particles were determined with PCS and TEM. The determination results revealed that concentrations of the compound surfactant and polymerization temperatures etc. affect the shape and size of polymer particles obviously. The experimental results show that with increasing the level of [E], [ I] and T, polymerization rate increases. And with increasing the content of [E] and the ratio of [SDS]/[CA], the particle size of polymer latexes and the dispersion index of the particles size decrease; but with increasing the content of [I] and temperature the particle size of the polymer latexes and also the dispersion index of the particles size increase.