Thermal Decomposition Characteristics of Mg (NO3)2·6H2O and MgCl2·6H2O Composite as Phase Change Material

The thermal decomposition characteristics of Mg (NO3)2·H2O and MgCl2·6H2O composite were studied by integrated thermal analysis. Results show that there are five steps during the thermal decomposition of phase change material (PCM): the starting temperature of each step is 35.5°C, 93°C, 196°C, 260°C and 318°C, respectively. PCM was calcined at different temperatures at each decomposition step. The composition and morphology of the calcined product was characterized by XRD and SEM. Two major reactions including dehydration and hydrolysis occur in the thermal decomposition progress. Dehydration is the main process below 196 °C, while hydrolysis is predominant process when the temperature is higher than 196 °C.