PBA/PMMA型核壳结构增韧剂的合成及表征

采用传统乳液聚合、无皂乳液聚合及其扩径聚合的方法，得到了粒径从０．０７８ｕｍ至１．３８ｕｍ的窄分布的ＢＡ（丙烯酸丁酯）为主单体的ＰＢＡ橡胶核，然后，进行ＰＭＭＡ的壳层种子接枝乳液聚合，得到ＰＢＡ／ＰＭＭＡ核壳结构胶乳，乳液经破乳过滤干燥后得到核壳结构增韧剂，发现随着橡胶相交联剂用量的增加，ＰＢＡ胶粒表现双键含量增加；核壳复合粒子表观羧基的含量可以用电位滴定法获得。实验表明，进行壳层混合单体（ＭＭＡ、ＭＡＡ）接枝时羧基主要分布在胶粒的浅层；核壳比对复合粒子的形态有较大影响。利用ＬＳ激光粒径仪测得胶粒的大小及其分布；同时，ＴＥＭ照片显示了核壳粒子的形态和尺寸。

PREPARATION AND CHARACTERISTICS OF PBA/PMMA CORE-SHELL PARTICLES AS TOUGHER

A series of PBA core PMMA shell particles as tougher were prepared using conventional emulsion polymerization, less emulsifier emulsion polymerization and free emulsion polymerization. It is found that the vinyl groups content of PBA rubbery core increases with the amount of cross linking agents increased and core shell ratio(mass) has great effect on the morphology of complex particles. The carboxyl quantities on the surface of core shell particles were determined by potentiometric titration. Results show that methylacrylic acid, which is loaded, is distributed on the surface of particles. The morphology of latex is determined by transmission electron microscope. The size and its distribution of latex particles were measured by LS counters particle size instrument.