Emulsifier-minor emulsion copolymerization of BA-MMA-St-MAA (or AA)-N-MA



A novel emulsion polymerization technique referred to as emulsifier-minor emulsion polymerization was achieved by the copolymerization of methyl methacrylate, butyl acrylate, and styrene (MMA-BA-St) with a combination of water-soluble ionic monomers [methacrylic acid (MAA) or acrylic acid (AA)] and nonionic monomers (N-methylol acrylamide). In the technique, water-soluble monomers play a crucial role in the stabilization of the latex particles as they can be bound to the particle surface and form a hydrate protective layer, which exhibits steric and/or electrostatic effects to prevent particle coagulation. The minor but over its critical micelle concentration emulsifier sodium alkylated diphenyl ether disulfonate (DSB) results in the nucleation of particles mainly by the micelle nucleation mechanism and thus determines the polymerization rate, the particle size, and the number. The film water resistance of the latices can be improved, and the foaming capacity of can be lowered by using technique instead of conventional emulsion polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2923–2929, 2004