Synthesis and characterization of ditetradecyl succinate and dioctadecyl succinate as novel phase change materials for thermal energy storage

Abstract

This paper deals with the synthesis, characterization, thermal properties and thermal reliability of 1-tetradecanol and 1-octadecanol-succinic acid esters as a novel solid–liquid phase change materials (PCM) for thermal energy storage (TES). Ditetradecyl succinate (DTS) and dioctadecyl succinate (DOS) were synthesized by using succinic acid and excessive amount of fatty alcohol under vacuum and without catalyst. The esterification reaction yield was found above 95%. High purity ester compounds were characterized structurally by 1H nuclear magnetic resonance (1HNMR) and fourier transform infrared (FT-IR) spectroscopy techniques as thermophysical properties were investigated using a differential scanning calorimeter (DSC) and a thermogravimetric analyzer (TGA). DSC method was exploited for determination of phase change temperature, enthalpy, total enthalpy and specific heat (Cp) of DTS and DOS. Thermophysical properties of the produced esters were similar to fatty alcohols. Phase change temperatures and enthalpies were slightly lower than those of pristine fatty alcohols which were explained by the succinate distortion replaced by hydrogen bonding interactions. The DSC analyses pointed out that the phase change temperatures of TDS for heating period were between 47 °C and 46 °C as corresponding enthalpy for cooling period was between 202.4 and 197.5 Jg-1 respectively. The phase change temperature and enthalpy of DOS were between 64 °C and 63 °C and 194.9 and 191.7 Jg-1 respectively. In addition, the thermal cycling test including 1000 accelerated cyclings was conducted to determine the thermal reliability of the synthesized PCMs and structural and thermal consistency of the material were checked by post FT-IR and DSC analysis. Morphology and thermal endurance limits of the DTS and DOS were also investigated using POM and TGA respectively. Based on the results, it was concluded that the synthesized novel PCMs had considerable potential due to their satisfactory thermal properties, thermal reliability and stability.