Study on preparation and thermal property of binary fatty acid and the binary fatty acids/diatomite composite phase change materials

This study prepared a series of binary phase change materials by mixing decanoic acid, dodecanoic acid, hexadecanoic acid and octadecanoic acid each other. The phase-transition temperature of binary fatty acid and its corresponding mixing proportion are calculated with phase diagram thermodynamic method. The results are verified by the experimental result of the heat absorption curve and the Differential Scanning Calorimetry (DSC) analysis curve. The results show that the calculation method of phase diagram thermodynamic calculation can be taken as a basis for mixing proportion of binary fatty acid phase change materials. In addition, the decanoic–dodecanoic acid/diatomite composite phase change material (PCM) are prepared and its microstructure, thermal property and thermal reliability are characterized. The result shows that the decanoic–dodecanoic acid is uniformly adsorbed into diatomite and the form-stable PCM are formed. The phase-transition temperature and the latent heat of the decanoic–dodecanoic acid/diatomite composite PCMs is 16.74 °C and 66.8114 J/g, respectively.