Light scattering study of structure of dispersion particles based on ethyl acrylate-methacrylic acid copolymers

Structural changes of colloid particles of ethyl acrylate-methacrylic acid (0–70%) copolymers on addition of alkali (pH∼9) or methanol were investigated. In addition to the feeding time of the monomer mixture, the content of methacrylic acid in the copolymers has been shown to influence dissolution of dispersion particles prepared by semicontinuous emulsion copolymerization. The longer the feeding time leading to higher polymer solids and the lower the acid content in the copolymer, the more limited was dissolution of disperse particles. On the basis of consistency of the results obtained in both media, this behaviour was explained in terms of a crosslinked structure of the copolymer due to chain transfer reactions.