P(MMA-EA-AA)共聚物组成对无皂乳胶粒碱处理后结构形态的影响——异型结构粒子的形成

INFLUENCES OF COPOLYMER COMPOSITIONS ON THE MORPHOLOGY OF P(MMA-EA-AA) SOAP-FREE LATEX PARTICLES PREPARED IN ALKALI POSTTREATMENT —— THE GENERATION OF ANOMALOUS PARTICLES

采用批量法无皂乳液聚合技术合成了粒径窄分布的甲基丙烯酸甲酯(MMA) - 丙烯酸乙酯(EA)- 丙烯酸(AA)三元共聚物胶乳,并通过碱后处理,制备出了具有异型结构的乳胶粒,探讨了AA用量及MMA /EA质量比对胶粒结构形态的影响.结果表明,当AA含量大于0 .0 4mol时,胶乳中开始出现异型结构粒子,随着AA用量的增加和MMA/EA质量比的减小,异型粒子在胶乳中所占比例增加,胶粒体积先增大后减小.当EA用量较高时,粒子边界模糊,异型结构不明显.

Monodispersed latex particles were synthesized by soap-free batch emulsion polymerization of methyl methacrylate(MMA), ethyl acrylate (EA) and acrylic acid (AA) and the anomalous structure in the particles were obtained after alkali posttreatment. Effects of AA amount and the mass ratio of MMA to EA on the latex properties before and after the posttreatment were investigated. Results showed that when AA amount was more than 0.04 mol, anomalous particles were generated and heterogeneity in the formation of anomalous structure was observed in the treated latices. With the increase of amounts of AA and the decrease of the mass ratio of MMA to EA, the percentage of anomalous particles increased, and their volume expansion increased and then decreased. The edge of particles blurred and the anomalous structure was not obvious in TEM photographs as large amount of EA was used.