水滑石分散剂用量对热膨胀微胶囊的粒径及其芯材含量的影响

Effects of Hydrotalcite Dispersant on Particle Size and Core Loading of Thermal Expansion Microcapsules

在悬浮聚合体系中以水滑石(LDH)作为分散剂制备的聚合物为壳体,正己烷为芯材的微胶囊。微胶囊受热后壳体软化、芯材气化产生热膨胀效果。改变LDH用量探究微胶囊粒径和芯材含量的变化规律。利用扫描电子显微镜、热失重仪、静态热分析仪分析了不同LDH用量时制得的热膨胀微胶囊的微观形貌、粒径、发泡剂含量和膨胀性能。结果表明,当LDH的用量增加到5%(以水相质量为基准,下同)时,微胶囊表面光滑,球形较完整,平均粒径降到11μm,发泡剂含量提高到16%(质量分数,下同),热膨胀性能良好,D_(max)达到750μm。

Thermal expansion microcapsules based on an n-hexane core and a polymeric shell were synthesized through suspension polymerization with hydrotalcite as a dispersant. The thermal expansion effect could be obtained from the evaporation of core materials after the microcapsules were heated to soften the shell. The morphology, particle size and selling properties of microcapsules were characterized by scanning electron microscopy, thermogravimetric analysis and static thermal analyzer, andthe effect of hydrotalcite content on the particle size and core loading of microcapsules were investigated. The results indicated that the microcapsules exhibited a regular morphology with a smooth surface and an average particle size of 11 μm when 5 wt % of hydrotalcite was added. The microcapsules also achieved an improved thermal expansion property with a dmax value of 750 μm when 16 wt % of foaming agent was loaded.