Preparation of acrylate polymer latex with hollow structure

The polymer particles, which consist of the core including ethyl acrylate and methyl methacrylate, the intermediate shell including ethyl acrylate, methyl methacrylate and acrylic acid, and the outer shell including styrene, acrylic acid and methacrylic acid, were synthesized by semi continuous seeded emulsion polymerization in the absence of emulsifiers. The latex particles prepared were treated in alkali and acid solution subsequently. Particles sizes and morphologies were characterized by TEM. The influences of the crosslinking agent, treating temperature, initial pH value during acid treating and the swelling agent on the formation of hollow structure were also investigated in detail. A series of results was got after careful study, which showed that hollow particles could be observed after treatments; the formation of the particles which have different glass transition temperature( T g) distributions from shell to core is the key to form hollow particles.