Miniemulsion Co-polymerization Of MMA/BA With Vinyl Silicone Rubber As Costabilizer

Vinyl silicone rubber (VSR) containing unsaturated C=C double bonds was used as costabilizer in the miniemulsion co-polymerization of methyl methacrylate (MMA) and butyl acrylate (BA). In the presence of sodium dodecyl sulfate (SDS) and VSR, miniemulsion of MMA/BA was prepared under ultrasonification, miniemulsion co-polymerization was then carried out with ammonium persulfate (APS) or 2, 2-azobisisobutyronitrile (AIBN) as initiator at 65. Shelf life of the miniemulsion with different costabilizers and VSR concentrations were measured. Effects of variations on the rate of co-polymerization and particle size and particle size distribution were investigated, including reaction temperatures, molecular weights of VSR, types of costabilizer, concentrations of VSR, solid contents, concentrations of SDS and different initiators. The differences between the mini- and macro-emulsion co-polymerization processes were simply discussed. The electrolyte stability of the latices, adhesion strength and the water adsorption of latex films were also studied. Whether APS or AIBN as initiator, an attempted explanation of the locus of free-radicals formation and initiation was proposed. The bonds between polyacrylate and VSR were confirmed by solvent extraction, FT-IR spectra, and 'H-NMR analysis. The effects of the adding MAA on film performance were also simply discussed.