Preparation, Phase Diagrams and Characterization of Fatty Acids Binary Eutectic Mixtures for Latent Heat Thermal Energy Storage

Abstract

A series of fatty acid binary eutectic mixtures were prepared by using capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid (CA, LA, MA, PA, and SA) as raw materials. The phase diagrams of these fatty acid binary eutectic mixtures were drawn using the Schrader equation. The thermal properties and structure were determined using differential scanning calorimetry (DSC). The thermal stability was assessed using thermogravimetric analysis (TGA) and thermal cycling tests. DSC analysis results showed that the phase change temperature of these fatty acid binary eutectic mixtures is between 17.7 °C and 57.1 °C, and the phase change latent heat is between 145.2 J/g and 193.0 J/g. The results of TGA and thermal cycle tests showed that these fatty acid binary eutectic mixtures have good thermal stability and long-term cycle thermal reliability. These results indicated that these binary eutectic mixtures of fatty acids were suitable as thermal energy storage materials for low-temperature systems.