Nonionic reactive surfactants. Part 2. Core–shell latexes from emulsion polymerization

Abstract.

Nonionic polymerizable surfactants (surfmers) with different reactive parts (i.e. methacrylic, allylic, maleic and vinylic) and nonreactive analogs have been applied in emulsion copolymerization of styrene and butyl acrylate in a seeded semibatch process. Stable core–shell latexes at 35% of solid contents with a low level of coagulum and controlled particle size (according to the right amount of surfactant engaged in the emulsion polymerization process) have been obtained. Some of them, owing to the reactivity ratio of the polymerizable group versus the monomers used, are stable to freeze–thaw cycles, electrolytes and organic solvents such as acetone. The incorporation yields of each surfmer were then investigated by precipitation of the latexes in acetone. It was observed that the nonreactive surfactant as well as the maleic one are not incorporated, while the methacrylic surfmer is fully incorporated. The two other surfmers (allylic and vinylic) are partly at the surface of the particles, but also form oligomers soluble in acetone.