Preparation and properties of long chain alkyl eutectic phase change materials

Based on the good compatibility of long-chain alkyl groups, with eicosane (ES), octadecane (OC), lauric acid (LA) and hexadecanol (HD) as raw materials, three eutectic phase change materials (ES-LA, OC-LA and OC-LA-HD) were prepared by melt blending method. The optimum mass ratio of eutectic points was calculated by Schröder formula, and was determined as m(ES)∶m(LA) = 0.61∶0.39, m(OC)∶m(LA) = 0.74∶0.26 and m(OC)∶m(LA)∶m(HD)=0.61∶0.21∶0.18, combing the results of step-cooling curve and DSC analysis. The eutectic temperatures were 30.3, 25.4, 21.9 ℃, respectively, which were consistent with the theoretical calculation results. The chemical structure, crystallization behavior, heat storage capacity, and thermal stability of eutectic phase change materials were evaluated and analyzed by FTIR, XRD, TGA and DSC. The results showed that three eutectic phase change materials were combined by physical interaction without chemical reaction. The phase transition temperatures were between 18~32 ℃, lower than any single component, while the phase transition enthalpy values were >190 J/g, indicating good thermal stability and cycle stability. © 2024 Fine Chemicals. All rights reserved.