Preparation and Thermal Properties of a New Low Eutectic Mixture of Myristic Acid–Palmitic Acid–Tetradecanol

In this work, myristic acid–palmitic acid–tetradecanol (MA–PA–TD) ternary composite phase-change materials were prepared by the melt blending method. First, the MA–PA phase-transition temperature was 43.7 °C and the optimal mass ratio was 70:30 using the step cooling curve. The minimum eutectic point of MA–PA–TD was determined, the optimal mass ratio of MA–PA/TD was 54:46, and the phase-transition temperature was 28.6 °C. The phase-transition temperature and enthalpy of MA–PA composite phase-change materials were 45.98 °C and 171.6 J/g respectively, and the phase-transition temperature and enthalpy of MA–PA–TD were 29.64 °C and 162 J/g by differential scanning calorimetry (DSC), respectively. The thermal storage and exothermic experiments of MA–PA–TD phase-change materials were carried out; the temperature range of MA–PA–TD was consistent with that of the DSC experiment during the phase transformation, indicating that MA–PA–TD had good heat storage capacity. It was found by infrared spectrometry that the spectral curves of MA–PA–TD composite phase-change materials were simply superimposed with those of MA, PA, and MA–PA, and no chemical reaction occurred. The MA–PA–TD composite phase-change material had excellent stability after 300 cold and hot accelerated cycles.