基于小分子液滴为模板单分散聚合物/SiO2复合微球的可控制备及形成机理研究

In recent years, the synthesis of organic-inorganic nanocomposite microspheres is an topic of research both home and abroad. They combine the advantages of the inorganic material and the organic polymer these composite particles. Moreover, they possess the special properties of nanoparticles, which can improve the characterization functions of the materials and even offer them many other new functions. How to control preparation of the polymer/SiO2 nanocomposite microspheres is a difficulty and challenge. Small molecular droplet is intended to form using styrene and butyl acrylate as polymerizable monomers, 1-vinylimidazole (1-VID), 2-(methacryloyl)ethyltrimethylammonium chloride(MTC), 4-vinyl pyridine (4-VP) as auxiliary monomer. Based on these small molecular droplets, polymer/SiO2 nanocomposite microspheres with different particle size and SiO2 adsorption were controlled prepared. The formation mechanism of the composite microspheres will be discussed, these composite microspheres were expected to be high wear-resisting coating. The relation on the structure and properties of polymer/SiO2 nano composite microspheres were deep studied. The influence factors to prepare the monodisperse nanocomposite particles, such as controlled way, relative parameters, prepared condition will be explored. The template relation between small molecular droplets and polymer/SiO2 nano composite spheres will be further investigated. The formation mechanism of the nanocomposite microspheres will be deep discussed.These polymer/SiO2 nano composite emulsions will be used as functional coating. The influence factors of using, such as the particle size, size distribution of composite microsphere, the kind of monomers, the ratio of polymer/inorganic particles will be evaluated. In order to provide the foundation for further develop the high wear-resisting of organic and inorganic compound nano coating.

具有有机和无机材料特性的有机无机复合微球因其独特的性能在功能涂层等方面的应用越来越受到人们的青睐。如何可控制备聚合物/SiO2纳米复合微球是一个难点和挑战。本课题拟以苯乙烯和丙烯酸丁酯为可聚合单体，与1－乙烯基咪唑，甲基丙烯酰氧乙基三甲基氯化铵，4-乙烯基吡啶等功能辅助单体形成小分子液滴，然后以小分子液滴为模板可控制备不同粒径大小和SiO2吸附量的聚合物/SiO2纳米复合微球，探讨复合微球的形成机理，预期作高耐磨涂料而发挥作用。深入研究复合微球结构及其性质，探索实现单分散复合粒子大小、粒径分布和无机粒子吸附量控制的途径、参数及其条件。进一步考察小液滴模板与聚合物/SiO2纳米复合微球的模板机制；深入研究纳米复合微球的形成机理；探索复合微球粒径、粒径分布、单体种类、聚合物/无机粒子比例等因素在功能涂层中应用的影响规律；为进一步开拓具有高耐磨的有机无机复合纳米涂料提供基础。

有机-无机纳米复合微球的合成是国内外的一个研究热点，这种有机-无机复合微球兼有有机材料和无机材料的优点，因而可望大大改善材料的现有性能甚至获得许多新的功能。在制备高强度复合涂层、新型复合磁性材料、高耐磨、功能涂层、新型发光材料和新型导电聚合物以及药物控释、生物医疗等领域中具有十分广阔的应用前景。如何可控制备聚合物/SiO2纳米复合微球是一个难点和挑战。本课题以苯乙烯和丙烯酸丁酯为可聚合单体，与辅助单体甲基丙烯酰氧乙基三甲基氯化铵、乳化剂CTAB，CA-897形成小分子液滴，然后以小分子液滴为模板,可控制备不同粒径大小和SiO2吸附量的聚合物/SiO2纳米复合微球，探讨复合微球的形成机理。深入研究了复合微球结构及其性质，探索实现单分散复合粒子大小、粒径分布和无机粒子吸附量控制的途径、参数及其条件。. 结果表明：无论是阳离子乳化剂体系还是非离子乳化剂体系，基于小分子单体液滴均可以制备得到单分散性好的复合微球，聚合物微球为核，二氧化硅吸附在聚合物表面，聚合物/SiO2纳米复合微球呈草莓型结构。乳化剂的量、二氧化硅添加量、辅助单体用量以及超声条件等制备工艺对复合微球的形成、复合微球的粒径及SiO2吸附量均有影响；制备工艺对复合乳液及乳胶膜的性能有影响。复合乳液具有良好的机械稳定性、稀释稳定性和耐电解质稳定性，而冻融稳定性较差，既耐酸又耐碱。纳米乳液呈现出良好的成膜性。初始二氧化硅用量和软单体BA的含量对乳胶膜的硬度、耐磨性能、光泽度以及耐水性能度影响较大。随着初始二氧化硅用量的加大，乳胶膜的硬度和吸水率显著上升；而BA用量的增加更有利于复合膜的光泽度增强。. 根据实验结果和对照实验，我们推断复合微球的形成机理是电荷作用，是基于聚合物微球表面的正电荷和二氧化硅粒子表面的负电荷的电荷相互作用，最后促成了复合微球的形成。本项目为合成草莓型有机无机纳米复合微球提供了较好的合成路线，为进一步开拓具有高耐磨的有机无机复合纳米涂料提供基础。