Preparation of hollow polymer particles encapsulating functional substance and its application

具有中空结构的聚合物颗粒在许多工业领域受到了广泛的关注。所述颗粒用作微胶囊、减重剂或隔热剂，并且由于其高光散射能力而应用于涂层和成型组合物中的遮盖剂或不透明剂。我们已经成功地通过种子聚合制备了微米大小的、单分散的、交联的、在中心有一个空心的聚合物颗粒。二乙烯基苯(DVB)/甲苯液滴虽然是多分散的，但可溶解聚苯乙烯，采用悬浮聚合法制备了类似的中空聚合物颗粒。空心结构的形成是基于相分离聚合物在液滴界面的自组装。该方法被命名为相分离聚合物自组装法（SaPSeP）。为了更详细地阐明空心颗粒的形成机理，本研究讨论了PDVB在液滴中的相分离、液滴内的粘度以及液滴大小对空心结构形成的影响。早期的相分离是空心结构形成的必要条件。由于低转化率时液滴内粘度较低，PDVB可以在液滴界面处移动吸附。PDVB微凝胶在聚合液滴中相分离后的迁移率是中空结构形成的重要因素。采用SaPSeP法制备包封扁柏醇或磁铁矿的复合颗粒。并将该方法应用于悬浮液体系中的多加成反应。该多加成反应体系满足SaPSeP法制备空心颗粒所需的条件。实际上，在甲苯蒸发后，成功地制备了中心有一个空心的固化环氧树脂颗粒。

Polymer particles with hollow structures have gotten a lot of attention in many industrial fields. Such particles are used as microcapsules, weight-saving or thermal insulation agents, and are applied to hiding or opacifying agents in coating and molding compositions because of their high light-scattering ability. We had succeeded in preparing micron-sized, monodisperse, crosslinking polymer particles having a single hollow at the center by seeded polymerization. Similar hollow polymer particles were produced by suspension polymerization for divinylbenzene (DVB)/toluene droplets dissolving polystyrene though they were polydisperse. The formation of the hollow structure is based on the self- assembling of phase separated polymer at the interface of the droplet. The method is named the Self-assembling of Phase Separated Polymer (SaPSeP) method.In this research, in order to clarify the formation mechanism of hollow particles by the SaPSeP method in more detail, the effects of phase separation of PDVB in the droplets, viscosity within the droplet and its size on the formation of the hollow structure were discussed. The phase separation in the early stage was required point for the formation of the hollow structure. Since the viscosity in the droplet is low at the low conversion, the PDVB can move and adsorb at the interface of the droplet. The mobility of PDVB microgels after the phase separation in polymerizing droplet was important factor for the formation of the hollow structure. The SaPSeP method was developed to produce composite particles encapsulating hinokitiol or magnetite. Moreover, the method was applied to the polyaddition reaction in a suspension system. The polyaddition reaction system satisfied the required conditions for the preparation of hollow particle by the SaPSeP method. In actual, cured epoxy resin particles having one hollow at the center were successfully prepared after evaporation of toluene.