【摘要】 用羟丙基甲基纤维素HPMC对无机粒子SiO2 进行胶囊化处理。结果表明 ,包覆温度为 6 0℃左右时 ,包覆量最大。SiO2 粒子上的包覆物量随着包覆时间的延长和 pH值的减小而增加。将包覆无机粒子的纤维素与甲基丙烯酸甲酯 /甲基丙烯酸丁酯 (MMA/BMA)接枝共聚合。采用IR、差热分析方法和透射电镜对复合粒子和其表面形貌及其在PVC基体中的分散状况进行了表征。结果表明 ,表面包覆的SiO2 上实现了MMA/BMA的接枝共聚合。复合粒子中的SiO2 粒子质量分数增加 ,复合物的热稳定性提高。未经表面包覆接枝的无机粒子团聚在一起 ,而经表面包覆接枝后的SiO2 粒子在PVC中均匀地分散后 ,材料的冲击强度和拉伸强度分别提高 42 3%和 41%。更多还原

【Abstract】 A kind of water-soluble hydroxyl propyl methyl cellulose(HPMC) has been encapsulated on the fine SiO 2 particles, and some factors, such as pH value of the medium, encapsulation time and temperature were examined. The results showed that at ～60 ℃ the highest amount of HPMC could be encapsulated on the SiO 2 surface, and it increased with increase of time and decrease of pH value. The graft copolymerization of methylmethacrylate(MMA) and butylmethacrylate(BMA) has been carried out on the surface of SiO 2/HPMC particles successfully. Encapsulated SiO 2 particles being dispersed in PVC have higher impact strength and tensile strength than that of control SiO 2 sample in 42.3% and 41%, respectively.更多还原