聚硅氧烷大单体与丙烯酸酯乳液共聚合

Emulsion Copolymerization of Polysiloxane Macromonomer and Acrylates

将具有交联作用的端乙烯基聚硅氧烷大单体 (Si 180 0 ) ,与丙烯酸酯单体进行乳液共聚合 ,制备了最高的质量分数为 2 0 %的Si 180 0一系列硅丙乳液。通过对聚合产物交联程度和交联物的红外光谱分析表征、聚合反应转化率、乳胶粒的粒径大小和分布 ,以及乳胶膜的耐水性能和力学性能的测试 ,结合部分乳胶粒形态分析 ,探讨了聚合条件对共聚的影响。结果表明 ,所得聚合物交联程度批量法为 11 6 % ,半连续法最高可达到6 2 6 % ,加料方式与加料时间对乳胶膜的吸水率和力学性能影响显著 ;聚合物交联程度随引发剂量增加而增大 ;随着Si 180 0用量的加大 ,聚合物乳胶膜的抗拉强度下降至 0 9MPa ,而断裂伸长率增加到 6 2 6 % 。

A series of emulsion with largest ω (Si 1800) up to 20% were prepared by emulsion copolymerization of vinyl terminal polysiloxane, acted as macromonomer cross linker, butyl acrylate and methyl methacrylate. The products were characterized by cross linking degree, IR analysis of the cross linked parts, conversion of the monomers, size and size distribution of the latex particles, water resistance and mechanical property of the latex film. The influence of reaction condition on the copolymerization has been discussed based on the morphological analysis of some latexes. The results showed that semi continuous feeding process improves the cross linking degree of products to 62 6%, whereas batch process to 11 6%. Feeding process of reagents and feeding time also show effects on the water absorption and mechanical property of latex film. Higher cross linking degree was obtained when more initiator was used. With the increase of ω (Si 1800), the break stress of the latex film dropped to 0 9 MPa while break elongation ascended to 626% , and water resistance property of latex film was improved.