【作者】 李崇学；

【导师】 宋秋生；

【作者基本信息】 合肥工业大学 ， 材料学， 2009， 硕士

【摘要】 高性能低成本丙烯酸乳液是近年来建筑涂料研究方面的热点之一。有机硅改性的丙烯酸乳液具有较高的耐刷洗和抗粉化性能,在外墙建筑涂料中有良好的应用前景。目前,研究较多的是硅溶胶与丙烯酸乳液的冷混,冷混硅溶胶的丙烯酸乳液能够较好地改善乳液的耐水性和耐光性。普通硅丙乳液因分子链结构和活性基团不相容而带来的储存稳定性差、乳胶膜相分离严重等缺陷,影响了市场推广。近年来,利用有机硅改性丙烯酸酯乳液的研究日趋活跃,由于其综合性能良好,具有良好的开发前景。论文以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)通过乳液聚合形成种子,然后向种子乳液中滴加苯乙烯(St)和乙烯基三乙氧基硅烷(VTEOS),合成了以丙烯酸酯为核,有机硅为壳层的核壳型复合乳液。研究了单体和功能单体配比、反应温度、乳化剂用量等有机硅改性丙烯酸酯乳液合成与性能的影响。确定了乳液合成的最佳工艺条件。以苯乙烯(St)和乙烯基三乙氧基硅烷(VTEOS)为共聚单体,合成乳液种子,以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)混合单体为壳层单体,半连续法合成了以有机硅为核,丙烯酸酯为壳层的核壳型复合乳液。研究了单体和功能单体配比、反应温度、乳化剂用量等有机硅改性丙烯酸酯乳液合成与性能的影响。确定了乳液合成的最佳工艺条件。用预乳化工艺和半连续种子乳液聚合技术,合成出了具有核/壳结构的苯乙烯-丙烯酸丁酯-甲基丙烯酸甲酯-丙烯酸四元共聚苯丙乳液,粒径分布均匀,讨论了乳化剂和引发剂体系以及引发剂、交联剂用量等因素对乳液性能的影响,用TEM及FTIR表征了所得聚合物乳液的结构。更多还原

【Abstract】 In recent years, development of styrene-acrylic emulsion with high performance and low cost stays on one of the hottest subjects in the research field of architecture coatings. Silicone-modified styrene-acrylic emulsion has excellent properties like scratch/weather resistance and long time to go chalks etc. Thus there brings a good market prospect for it to be deployed in the architecture coatings as for external wall decoration applications. Styrene-acrylic emulsion mixing with silicate gel also has better properties on water resistance and weather resistance than those without adding it. This subject had been widely studied into to maximum extent by scientists in the world. However due to the limits that silicon molecular chain structure and styrene-acrylic component’s active groups is not well compatible with each other, there occurs with its poor applicaions from silicone modified acrylic emulsion such as settling of storage and serious separation of different latex films and so on., thus its commercial application is much effected.The research of using silicone-modified acrylic emulsion has become increasingly active in recent years, and there will be good prospects of development because it have better total performance than others.Herewithin being stated in this article, the seeds are synthesized through emulsion polymerization with MMA and BA, then into which styrene and VTEOS were added to produce organic composite latex with acrylic-core/silicon-shell. The effects resulting from a varity of reaction conditions on reaction control and emulsion’s performance was studied, for example, mass ratio of the monomer to functional monomer, reaction temperature and the amount of emulsifier. a series of optimal conditions to achieve sound performance were concluded.The organic silicon modified acrylic copolymer emulsion with core-shell structure was synthesized by semi-continuous emulsion polymerization, in which MMA, BA was used as core-monomers and St, VTEOS was used as shell-monomers. The influence of reaction conditions on the preparation and their performance was studied, eg mass ratio of the monomer to functional monomer, reaction temperature and the amount of emulsifier, optimal conditions were obtained.Styrene-acrylate emulsion with core-shell structure has been prepared based on styrene- butylacrylate-methyl methacrylate-acrylic acid terabasic polymer and by the use of pre- emulsification and semi-continuous seed polymerization technology, its particles distribution is in good equality and the demonstrated performance is extremely superior, where it is suitable in interior coating, adhesion, printing ink usage and so on.The influence of different emulsifier system, initiator system and the amount of initiator, modifying agents on the emulsion performance were studied.The prepared samples were characterized by FTIR, TEM. The result shows that the emulsion obviously possessed core-shell structure.更多还原