种子乳液聚合法制备多孔乳胶粒

用批量乳液聚合法制备了苯乙烯（Ｓｔ）———甲基丙烯酸甲酯（ＭＭＡ）二元共聚种子乳液Ｓ１以及Ｓｔ ＭＭＡ 丙烯酸（ＡＡ）三元共聚种子乳液Ｓ２，通过连续法无皂种子乳液聚合合成了一系列不同ＡＡ或ＭＡＡ（甲基丙烯酸）含量的Ｓｔ、ＭＭＡ三元共聚乳液．将所得复合胶乳进行碱／酸分步处理，得到具有多孔结构的乳胶粒．用透射电镜对胶粒形态进行了表征，考察了不饱和酸种类和用量、碱处理初始ｐＨ值及溶胀剂对胶粒成孔的影响．

PREPARATION OF MULTIHOLLOW PARTICLES BY SEEDED EMULSION COPOLYMERIZASION

Seed latex S 1 consisting of styrene(St) and methyl methacrylate(MMA), and S 2 consisting of St. MMA and AA(acrylic acid), were first prepared by batch process, then a series of St MMA AA or MAA(methyl methacrylate) terpolymer latexes containing different amount of unsaturated acid monomers were synthesized by continuous seeded emulsion copolymerization in the absence of emulsifiers, and the composite latexes were then treated by alkali and acid subsequently at 90℃ for 3h. Particle size and morphologies were characterized by TEM using phosphotungstic acid as staining agent. The influence of swelling agent MEK(methyl methacrylate) and the initial pH value in the alkali treatment on the formation of multihollow were investigated. Experiments showed that multihollow particles, accompanied by the largest volume expansion, were observed after treatments for S 1/P(St MMA AA) using 8.0% mole of AA in the second step monomers.At the present conditions, AA is more suitable than MAA to prepare the desired multihollow latexes particles, and seed latex S 1 is more effective than S 2 on the forming multihollow structure in latex particles.