Abstract: 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.