EFFECT OF INITIAL POLYMERIZATION CONDITIONS ON THE STRUCTURE OF ETHYLACRYLATE-METHACRYLIC ACID COPOLYMER LATEX-PARTICLES

Non-seeded semi-continuous emulsion copolymerizations of ethyl acrylat e-methacrylic acid (85/15 wt. ratio) were carried out using various em ulsifier and initiator concentrations and phase partitioning. The effe ct of the polymerization conditions on the particle size and morpholog y was investigated by means of scanning electron microscopy, light sca ttering and viscometry. Disintegration into smaller particles on alkal i addition confirmed coagulative mechanism of the panicle growth. This is distinct mainly if the colloidal stability of the polymerizing sys tem is reduced due to lower concentration of the emulsifier and higher concentration of peroxydisulfate initiator which suppress double laye r thickness of forming particles.