Study on controlling particle growth in seeded emulsion polymerization with regulated coagulation based on the electrostatic interactions

30wt% solid content, anionic seed copolymer latex P(methyl acrylate-co-methyl methacrylate) was prepared by conventional emulsion polymerization, and then the seeded emulsion polymerization was carried out accompanied with the electrostatic coagulation during the reaction in the presence of counter-ion species, such as cationic monomer and initiator. In this article, effects of cationic monomer (dimethyl aminoethyl methacrylate, DM) content, secondary monomer to seed polymer weight ratio, M/P and amount of emulsifier (polyoxyethylene nonylphenylether with 23 units of ethylene oxide, PEO23) were investigated on the effective particle growth and the stability of final latex. With 10wt% DM in monomer, M/P ratio at 2.0 were recommended. An optimal policy for handling the emulsifier content without the nucleation of secondary particles while achieving the controlled coagulative growth was proposed from the observations of polymer yield and particle size during the polymerization.