ONE-STEP SYNTHESIS OF POLY(METHACRYLIC ACID) MACROMONOMERS AND APPLICATION TO SOAP-FREE EMULSION COPOLYMERIZATION WITH STYRENE

Allylic sulfides such as alpha-(tert-butylthiomethyl)styrene and alpha-(2-hydroxyethylthiomethyl)styrene worked as effective chain transfer agents in the radical polymerization of methacrylic acid, to afford a one-step synthesis of water-soluble macromonomers with the 2-phenylallyl end groups. The macromonomers were found to be effective, particularly in the partially neutralized form, in emulsion copolymerization with styrene in water, to give stable emulsions with nearly monodisperse, submicron-sized particles. The microspheres thus obtained are considered to have carboxyl groups densely bound on the surface as a result of an organized copolymerization.