保护胶体对聚甲基丙烯酸甲酯热敏型微胶囊性能的影响

采用乳液聚合法,以聚乙烯醇为保护胶体、染料隐色体为芯材、交联聚甲基丙烯酸甲酯(PMMA)为壁材,制备了热敏型微胶囊.利用红外光谱仪、粒度分析仪、扫描电子显微镜、热重分析仪、差示扫描量热仪和紫外-可见分光光度计表征了保护胶体不同质量分数下制备的微胶囊的结构、平均粒径及粒径分布、形貌、热稳定性、玻璃化温度和热敏释放性能等.实验表明,保护胶体质量分数为4.5%时,所制备的微胶囊的平均粒径最小,为189.7 nm,粒径分布最均匀,呈规则的球形,包覆率为95.0%,具有优良的热稳定性和良好的热敏释放行为.

Effect of Protective Colloid on Properties of Poly(methylmethacrylate) Heat-sensitive Microcapsule

Heat-sensitive microcapsules were prepared by emulsion polymerization by pouring an aqueous solution with poly(vinyl alcohol) as protective colloid into an organic solution with leucocompound as core material,crosslinked poly(methyl methacrylate)(PMMA) as wall material.The structure,particle size distribution,morphology,thermal stability,glass transition temperature and heat-sensitive release behavior of core materials of the resulting microcapsules of different protective colloid mass fractions were characterized by infrared spectrophotometer,scanning electronic microscopy,differential scanning calorimetry,thermogravimetry analysis and UV/visible spectrophotometer.The results showed that,the average particle size of the microcapsule was 189.7 nm,its particle size distribution was the narrowest and its surface was the smoothest,the core content of the microcapsule was as high as 95.0%,the microcapsule showed higher thermal stability and heat-sensitive release property when the protective colloid mass fraction was 4.5%.