Emulsion polymers of core-shell styrene-butyl acrylate: the effect of feeding and aging time on particle size distribution

Core-shell polymers in the particle size range 200-300 nm having a monodisperse distribution and opal color are prospective materials for coating applications. The emulsion polymerization of the core-shell was done using two monomers with significantly different refractive indices styrene for the hard monomers and butyl acrylate for the soft monomers. The feeding and aging time were varied, with particle size shown to increase with decreasing feeding time. Increasing the aging time increased conversion but had no effect to the particle size even after two hours producing particles in the 200-300 nm range. The obtained core-shell emulsion polymers were characterized by determining particle size and polymers morphology by TEM