种子微悬浮聚合法制备微胶囊相变材料

Preparation of Microcapsules by Seeded Micro-suspension Polymerization

摘要:

结合种子乳液聚合法和微悬浮聚合法的特点，建立了种子微悬浮聚合法，目的在于改善微胶囊的形貌结构和提高微胶囊的性能。以苯乙烯（St）和二乙烯基苯（DVB）为壁材聚合单体，偶氮二异丁腈（AIBN）为引发剂，羟丙基纤维素（HPC）和碳酸钙（CaCO3）为复合分散剂，采用种子微悬浮聚合法制备交联聚苯乙烯（PS）包覆硬脂酸丁酯微胶囊。利用扫描电子显微镜（SEM）、差示扫描热量仪（DSC）、粒度分析仪和热重分析仪（TG）等表征了微胶囊的形貌和性能，研究了种子微悬浮聚合法及交联剂、分散剂、引发剂和搅拌速率等因素对微胶囊形貌结构和性能的影响。结果表明，种子微悬浮聚合法制备的微胶囊呈更规整的球形结构，粒径分布均匀，相变潜热增大29.4%，包覆率提高15.1%；随DVB用量的增加，壁材的交联度增大，密封性增强，热稳定性提高；当复合分散剂W(HPC):W(CaCO3)=2.2:1时，微胶囊相变潜热提高21.1%。

Abstract:

The phase change microcapsule were prepared by the method of seeded micro-suspension polymerization, which was combined to the advantage of seeded emulsion polymerization and micro suspension polymerization, with styrene (St) and divinylbenzene (DVB) crosslinked polystyrene (PS) as the outer membrane and butyl stearate as core, AIBN, HPC and CaCO3 were used as initiator and compound dispersing agent, respectively. The morphological, thermal behavior and properties of microcapsules were characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), particle size analyzer and thermogravimetric analyzer (TG). The influence of polymerization method, crosslinking agent and dispersing agent on the morphology and properties of the microcapsules were investigated. The results indicated that the microcapsules which was prepared by seeded micro-suspension polymerization have uniformly distributed granular diameters were regularly spherical, and the latent heat and the coating rate increased by 29.4% and 15.1%, respectively. The crosslinking density of wall material, the tightness and the thermal stability were enhanced with the increasing of DVB content. When the weight ratio of HPC and CaCO3) was 2.2:1, the latent heat increased by 21.1%.