Effect of posttreatment temperature on the formation of multihollow P(St-EA-AA) latex particles

摘要

Since porous polymer latex particles were prepared by Kowalski et al. for the first time and was used as plastic pigment in special coating, interest has been increasing in hollow-containing polymer latex particles owing to their direct and potential applications in special coating, drug delivery, and bimolecular immobilization. Two important preparation method of this kind of functional latexes were reported during the past several years: The first was offered by Vanderhoff et al, in which the hollow particles were obtained simply by drying hydrophilic/hydrophobic composite latex particles with soft alkali-swelling core and hard shell; The second, named "stepwise alkali/acid method", was reported by Okubo and his colleagues, in which the submicron-sized multihollow latex particles were synthesized by two-stage emulsion polymerization and followed by alkali/acid posttreatment. We have successfully synthesized monodisperse multihollow poly(styrene-methyl methacrylate-acrylic acid/or methyl acrylic acid) latex particles [abbreviated as P(St-MMA-AA/MAA)] using seeded emulsion polymerization, and the influences of organic acid, swelling agent, crosslinking agent, and the initial pH value of alkali/acid posttreatment on the multihollow generation of P(St-MMA-AA/MAA) were also investigated.