| Abstract: | A series of form‐stable phase change materials (FSPCMs ) comprising paraffin as the latent heat storage material, diurea as the supporting material and base oil as the performance improvement agent were prepared. The diurea was synthesized in the system of paraffin/oil directly. A series of characterization was carried out for a deep understanding of shape stability and material properties of diurea‐FSPCMs . The results showed that paraffin and base oil were packaged in the three‐dimensional supra‐molecular structures network which was formed by diurea. The dropping point of the prepared FSPCMs could reach 256 °C and the oil separation rate was as low as 1.19% at 100 °C for 30 h. The results of thermal properties tests showed that the prepared FSPCMs exhibited excellent thermal stability and the FSPCMs remained solid‐like state in the temperature range from 25 to 200 °C. This study proposes a novel method to prepare high‐temperature non‐flowing FSPCMs composites and methods to detect the thermal stability and shape stability of FSPCMs , which is helpful in understanding the shape stability mechanism and broadening the potential application of FSPCMs . |
