FORMATION MECHANISM OF SILICONE-RUBBER PARTICLES WITH CORE-SHELL STRUCTURE BY SEEDED EMULSION POLYMERIZATION

Silicone rubber particles with core-shell structure were prepared by p olymerization of vinyl monomers in the presence of crosslinked and lin ear poly(dimethyl siloxane-methyl vinyl siloxane) latex. The monomers were added with either continuous or swelled-continuous addition mode. The core-shell morphology of silicone rubber/polystyrene [PST] and si licone rubber/poly(methyl methacrylate-divinyl benzene) [P(MMA-DVB)] c omposite particles were obtained. The effects of monomer addition mode , the compatibilities of the monomers or their homopolymer with silico ne rubber, and the reactivity of polysiloxane with vinyl monomers on t he formation of the core-shell structure were discussed. (C) 1996 John Wiley & Sons, Inc.