Morphology of poly(butyl acrylate)/poly(styrene-co-methyl methacrylate) latex prepared by starved emulsion polymerization:: II.: Development of particle morphology

Heterogeneous latexes were prepared by a two-stage seeded emulsion polymerization process under monomer starved conditions at 80degreesC using potassium persulfate as the initiator and sodium dodecyl sulfate as the emulsifier. Poly(butyl acrylate) latexes were used as seeds. The second-stage polymer was poly(styrene-co-methyl methacrylate). By varying the amount of methyl methacrylate (NIMA) in the second-stage copolymer, the polarity of the copolymer phase could be controlled. It was found that the latex particles displayed different morphologies depending on the monomer ratio. The amount of MMA had a significant effect on the evolution of morphology. The morphologies were observed by transmission electron microscopy. In addition, the evolution of the particle morphology was predicted by the mathmatical model for cluster migration. The model gave the same trends as the experimental results. (C) 2002 Society of Chemical Industry.