苯乙烯-有机硅烷共聚物作为助稳定剂的细乳液聚合研究

Study on Miniemulsion Polymerization with St-Siloxane Copolymer as Co-Stabilizer

以苯乙烯(St)与甲基丙烯酰氧基丙基三乙氧基硅烷(TEPM)的共聚物P(St-TEPM)为助稳定剂,用于不同亲水性单体的细乳液聚合。考察了P(St-TEPM)助稳定剂在不同亲水性单体(St、甲基丙烯酸甲酯MMA、醋酸乙烯酯VAc)的细乳液聚合过程中对单体转化率、聚合物粒子粒径的影响及成核机理。结果表明,P(St-TEPM)单独作为助稳定剂用于不同单体(St、MMA、VAc)的细乳液聚合,亲油性较好的St和亲水性较好的VAc的聚合转化率分别为90.6%和63.8%,聚合物粒子的最终数目和单体液滴的起始数目(Npf/Nmi)分别为1.06和0.10。通过以上分析认为P(St-TEPM)可以作为细乳液聚合的助稳定剂使用,亲油性单体St聚合机理以单体液滴成核为主体。

Silane copolymer（P（St-TEPM））,which was synthesized by styrene（St） and 3-（Triethoxysilyl） propylmethacrylate（TEPM） via solution polymerization,was used as the sole co-stabilizer in miniemulsion polymerizations and its effects on the polymerization conversion ratios of the monomers,the effects of the latex particle size and the nucleation mechanism of the miniemulsion polymerization with different hydrophilic monomers（St,methyl methacrylate MMA and vinyl acetate VAc） were investigated.The results show,when silane copolymer was used as sole co-stabilizer in miniemulsion polymerization,the polymerization conversion ratios of the St,which is more lipophilic,and the VAc,which is more hydrophilic,are 90.6% and 63.8%,respectively,and the ratio of Npf / Nmi（Npf is the final number of the latex particles and Nmi is the number of monomer droplets at beginning） are 1.06 and 0.10,respectively.Based on the results obtained above,the conclusion may be obtained that the P（St-TEPM） can be used as co-stabilizer in miniemulsion polymerization,and the nucleation mechanism of lipophilic monomer St mainly is droplet nucleation.