A well encapsulating stearic acid composite phase change material sealed by calcium carbonate

A new type of microencapsulated stearic acid phase change material was synthesized by in-situ polymerization with calcium carbonate as the encapsulation material and nucleating agent to stearic acid. The thermal properties of microencapsulated stearic acid were investigated by differential scanning calorimetry, thermogravimetric analysis and hot disk. The maximum phase change enthalpy is about 139 J/g and 135 J/g in the melting and solidifying processes, which are higher than those of the stearic acid composite phase change materials previously reported. The optimum encapsulation ratio of the calcium carbonate to the stearic acid is about 79%. In addition, the samples exhibited a perfect spherical morphology, good thermal stability, shape stability, relatively well thermal conductivity and good thermal cycle life. The in-situ polymerization synthesis method used in preparing the stearic acid phase change microcapsules has been less studied.