室温交联型硅丙微胶乳的合成研究(1)硅烷单体对聚合稳定性和胶膜性能的影响

采用种子微乳液聚合工艺和单体半连续滴加法合成了室温交联型有机硅改性丙烯酸酯微胶乳，研究了硅烷单体种类和用量及其添加顺序等对聚合稳定和胶膜性能的影响。结果表明，使用含阻碍性铁新硅烷单体（C－1757）可明显抑制体系中的水解－缩合反应，提高聚合稳定性，而且随其用量增加，改性胶膜的交联密度增大，拉伸强度提高；延迟添加C－1757，可进一步提高聚合稳定性，但会降低胶膜的交联密度，拉伸强度先高后低，30／70处有一个最大值，所合成的硅丙微胶乳储存期可达长两年，与C－1757相比，硅烷单体A－174改性的胶膜具有更大的交联密度，而A－171改性的胶膜交联密度偏低，力学性能较差。

THE STUDY OF SYNTHESIS OF SILOXANE-ACRYLATE MICROLATEX CROSSLINKED AT ROOM TEMPERATURE(1) The Effect of Siloxane Monomers on the Stability of Polymerization and the Properties of Microlatex Film

The siloxane-modified polyacrylate microlatex was synthesized by seeded microemulsion polymerization and semi-continue process. The effects of structure and dosage of siloxane monomers as well as their adding sequence on the stability of polymerization and the properties of microlatex films were studied. Result indicates that the hydrolysis-condensation of siloxane in polymerization can be inhibited by using new siloxane monomer (C-1757) with hindered structure, and the stabilities of polymerization and storage are improved. Moreover, the microlatex films obtain higher crosslinked density and better tensile properties as the dosage of C-1757 increases. We also obtain the results that the stability of polymerization increases as the adding sequence of C-1757 was delayed, which decreases the crosslinked density of films at the same time. The tensile strength of modified films has a peak at adding sequence of 30/70. The siloxane-acrylate microlatex synthesized using C-1757 have a 2-year storage life. Compared to C-1757, the film modified with A-174 has higher crosslinked density and the one modified with A-171 have a low crosslinked density and poor tensile properties.