Study of poly(St/BA/MAA) copolymer latexes with bimodal particle size distribution

Polymer latexes with bi-modal particle size distribution were prepared by i ntroducing small amount of a second seed of polymer particles during the se micontinuous emulsion polymerization of styrene, butyl acrylate and methacr ylic acid. The polymerization was investigated by following the variation o f the particle size, the size distribution, the number of particles, the su rface tension and surfactant surface coverage at different stages of the po lymerization process. The results showed that both the size and size distri bution can be con trolled by the amount of second polymer particles. The am ount of small particles and the partition of monomers consumed for the grow th of small particles increased with increasing amount of second polymer pa rticles. It was also demonstrated that small particles grew more quickly th an the large ones, but to a limited extent. An introduction df small amount of additional surfactants had Mo significant effect on the particle size a nd size distribution of both types of particles. (C) 1998 John Wiley & Sons , Ltd.