聚甲基丙烯酸甲酯包覆水微胶囊的制备及性能

Preparation and characterization of microencapsulated water with poly (methyl methacrylate) as shell

为了优化水溶性物质微胶囊化工艺,并探究影响因素,在W/O反相乳液体系中,采用原位聚合法,通过自由基聚合成功制备了具有生物相容性的聚甲基丙烯酸甲酯(PMMA)为壁材、水为囊芯的微胶囊,并研究芯壁比、油水体积比、甲基丙烯酸(MAA)、交联剂甲基丙烯酸烯丙酯(AMA)对微胶囊性能的影响;通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、激光散射粒度分布分析仪(LSPSDA)、差示量热分析(DSC)和热重分析(TG)对微胶囊的形貌、结构、粒度分布、包覆率、热焓值及热稳性进行了分析.结果表明:微胶囊近似球形,具有核壳结构,粒径主要分布在0.5~1.5μm之间;芯壁比为1∶1时微胶囊的形貌最为规则,最佳油水相体积比为10∶1;加入交联剂和甲基丙烯酸的微胶囊包覆率分别提高了20%和30%左右,壁材中添加交联剂和甲基丙烯酸有助于提高包覆率.

In order to optimize the microencapsulation process of water -soluble substances, and explore the influencing factors, microcapsules containing water were prepared by in-situ polymerization in inverse emulsion system with biocompatible poly (methyl methacrylate) as shell by free radical polymerization. The influence of core-shell ratio, volume ratio of oil to water, methacrylic acid and crosslinking agent on the properties of microcapsules were discussed. The morphologies, core-shell structure, particle size distribution, encapsulation efficiency, and thermal stabilities of the microcapsules were characterized by scanning electron microscopy(SEM), transmission electron microscope(TEM), laser scattering particle size distribution analyzer(LSPSDA), differential scanning calorimetry(DSC), and thermal gravimetric analysis(TG). Results showed that the spherical microcapsules had a core-shell structure, and the distribution of particle size was in 0.5-1.5 μm. The morphology of the microcapsules was the most regular when the ratio of the core-shell was 1 ∶ 1, the best volume ratio of oil to water phase was 10 ∶ 1.The encapsulation efficiency increased by 20% and 30% respectively by adding crosslinking agent and methacrylic acid. The addition of crosslinking agent and methacrylic acid can improve the encapsulation efficiency significantly.