支化型有机硅/丙烯酸酯共聚乳液的合成及其性能

采用种子半连续乳液聚合,以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)为交联单体,以具有支化型大体积疏水基团的有机硅单体γ-甲基丙烯酰氧基丙基三(三甲基硅氧基)硅烷(MATS)为功能单体,与丙烯酸丁酯和甲基丙烯酸甲酯进行乳液共聚,合成了稳定的交联型高硅含量硅丙乳液。对乳液聚合过程及聚合物膜性能的测试结果表明,随聚合体系中MATS用量由0增加到占单体总质量的10%,乳胶粒子的z-均粒径(Dz)由133.5 nm减小到123.7 nm,粒径多分散指数由1.150减小为1.131;聚合物膜的水表面接触角由61°增大到78,°48 h吸水率由5.9%降低为2.5%。

Synthesis and Properties of Branched Organosilicon/Acrylate Copoymer Emulsion

Stable BA/MMA/MPS/MATS copolymer emulsions with high silicon content were prepared by seeded semibatch emulsion polymerization,in which MPS(γ-methacryloxypropyl trimethoxy silane) acted as a crosslinker and MATS(γ-methacryloxypropyl tris-(trimethylsiloxy)silane) was used as a novel reactive organosilicon monomer with branched Si—O—Si groups.The process of emulsion polymerization and properties of the copolymer latex were measured.It was found that when the MATS content in the polymerization system was increased from 0 to 10%,z-average diameter of the latex particles decreased from 133.5 nm to 123.7 nm,the polydispersity index decreased from 1.150 to 1.131,the water contact angle of the copolymer films rose from 61° to 78°,and the water absorption ratio lowered from 5.9% to 2.5%.These indicated that the incorporation of large branched hydrophobic group of MATS could provide the copolymer with excellent water-resistance.