改性硅溶胶/聚丙烯酸酯复合乳液的制备及性能研究

Research on Preparation and Properties of Modified Silicasol/Polyacrylate Composite Latex

为了提高无机纳米粒子在有机聚合物中的相容性,以及无机-有机复合材料的贮存稳定性,用硅溶胶和双丙酮丙烯酰胺(DAAM)制备出改性硅溶胶,然后以改性硅溶胶为核,以甲基丙烯酸甲酯(MMA)、α-甲基丙烯酸(MAA)和丙烯酸丁酯(BA)为原料,通过半间歇乳液聚合法制备出了核壳结构的改性硅溶胶/聚丙烯酸酯复合乳液(DAAM-SiO_(2)/WPA),并研究了硅溶胶对聚丙烯酸酯复合乳液和涂膜性能的增强作用。结果表明:用质量分数3%的双丙酮丙烯酰胺(DAAM)改性硅溶胶,制备的复合乳液的综合性能增强,水接触角为77.17°,吸水率为11.27%,拉伸强度为7.22 MPa,断裂伸长率为431.49%。TEM测试表明复合乳液具有核壳结构。相比较纯丙烯酸酯(WPA)涂膜,复合乳液涂膜的耐水性、热稳定性和力学性能都有显著提高。并且与聚丙烯酸酯乳液和硅溶胶的直接物理混合溶液(SiO_(2)/WPA)相比,改性硅溶胶/聚丙烯酸酯复合乳液的室温贮存稳定性超过12个月,无机相和有机相的相容性好。

In order to improve the compatibility of inorganic nanoparticles in organic polymers and the storage stability of inorganic organic composites,the modified silica-sol was prepared by silica-sol and diacetone acrylamide(DAAM). Then the modified silica-sol was used as the core,and methyl methacrylate(MMA),α-methacrylic acid(MAA)and butyl acrylate(BA)were used as raw materials,a modified silica-sol/polyacrylate composite latex(DAAM-SiO2/WPA) with core-shell structure was prepared by semi batch emulsion polymerization. The effect of silica-sol on the preparation of polyacrylate composite latex and the film was investigated. The results showed that the comprehensive properties of the composite latex prepared by 3% DAAM modified silica-sol were enhanced. The water contact angle was 77. 17°,water absorption 11. 27%,tensile strength 7. 22 MPa,and elongation at break 431. 49%. TEM image exhibited that the composite latex was a core-shell structure.Compared with pure waterborne polyacrylate film,the water resistance,thermal stability and mechanical property of the composite film were significantly improved. In addition,compared with the physical blending solution(SiO2/WPA)of polyacrylate latex and silica-sol,the storage stability of the modified silica-sol/polyacrylate composite latex exceeded 12 months at room temperature,and the inorganic phase and the organic phase indicated a better compatibility.