Preparation and characterization of a series of diol di-stearates as phase change heat storage materials

A series of solid–liquid phase change materials, diol di-stearates, were prepared via esterification of stearyl chloride with the respective diol (1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol) using pyridine as acid absorbent, and were then characterized by FT-IR, WAXD, POM, DSC and TGA measurements. All of the resulting diol di-stearates were apt to crystallize due to structural symmetry and flexibility of long alkyl groups. The DSC results indicated that the melting point of the prepared diol di-stearates varied from 38.5 °C to 56.4 °C, and phase change enthalpy lies in the range 134 kJ/kg–189 kJ/kg.