新型无机－有机杂化微球的制备及其在分离科学中的应用

Polymer microspheres have been widely used in science and industry, however there are still some common deficiencies such as lack of mechanical stability, easy in swelling or shrinkage and not enough thermal stability which leads to poor reproducibility and short service life of these microsphere materials. For using as chromatography stationary phase, the mechanical properties should be one of the first concerns since these materials have to resist the high pressure. So how to improve the mechanical property of the polymer based microspheres is an urgent and important issue to overcome. The emergence of the polyhedral oligomeric silsesquioxane (POSS) provided a very good hint to overcome these shortcomings since this kind of monomer or building blocks could greatly improve the mechanical and thermal stability of the conventional polymers as long as they were incorperated into the final product via covalent bonding or blending. And the final product consisting POSS monomers, called inorganic-silica hybrid materials. One can immagine that if the POSS was covalently incorperated into the polymer microspheres, the resulted inorganic-organic hybrid microspheres should exhit better mechanical and thermal stabity which could be more suitabe for chromatography stationary phases. So the aim of this project is to develop efficient method to covalently incorperate the POSS into the conventional polymer microspheres to increase the mechanical and thermal stability while maintaining the merits of these coventional microspheres. After systematic and extensive investigation of the synthesis process, monodispersed inorganic-organic hybrid microspheres with good mechanical, good thermal stability, narrow particle size distribution and high specific surface area could be obtained and applied in chromatographic separation materials.

有机聚合微球在生产生活中应用非常广泛，但仍普遍存在机械强度不高、易溶涨收缩或热稳定性不好的缺点,严重影响到操作过程的重现性及微球的使用寿命。如将其应用于色谱分离填料，良好的机械性能是众多前提之一。所以，如何提高有机微球的机械强度是制备有机色谱填料亟待解决的主要问题。多面体寡聚倍半硅烷(Polyhedral oligomeric silsesquioxane, POSS)有引入具有能提高有机聚合物机械性能及热稳定性的特点，如果能将POSS试剂引入到有机微球的制备的中，就可以得到机械性能显著提高的无机-有机杂化微球。此外，热稳定性的提高也可使该填料能在较高温条件下操作，加快分离分析过程。本课题研究的目的是探索有效的方法及操作过程将POSS试剂共价引入到高分子微球中。通过系统考察及优化制备条件，最终得到尺寸合适、粒径分布窄、比表面积高、机械强度好、热稳定性优良且适用于色谱填料的杂化聚合物微球。

本项目旨在利用多面体寡聚倍半硅烷（POSS)为单体或交联剂，制备具有高机械强度的有机-无机杂化微球，并将其作为高效液相色谱的填料用于分离分析中。在执行过程中，基本按照项目最初申请书中所列的方案进行。在第一阶段，因POSS试剂价格比较昂贵，反应单体中没有使用POSS试剂，选用了乙二醇二甲基丙烯酸酯（EDMA）作为交联剂，氯乙酸丙烯酯(ACA)作为功能单体，通过优化反应体系，包括溶剂，单体配比、温度、搅拌速率等参数，制备得到了大小较为均一，尺寸在1.5-2.5 um的微球材料。在制备的过程中，考察了各个条件对微球的大小和形貌的影响，可通过改变条件，在微球形貌实现一定程度的控制，不过微球的尺寸仍然难以提高。该微球的表面带了氯基团，可作为出发基质进行修饰。目前利用亲核取代反应对该微球进行了衍生，将其作为固相萃取填料用于样品的前处理。.在加入了POSS单体后，微球的形貌发生极具变化，尺寸明显变小，很多变为絮状沉淀。目前可得到的最大尺寸在1.5 um左右，在粒径分布上较为理想。机械强度及粒径分布两方面的评价还没有完成，如果机械强度优良，则可作为超高压液相色谱填料。