相变储能化合物CH_3COONa·3H_2O的热分解行为

Thermal Behavior of CH_3COONa·3H_2O as Phase Change Material

通过对CH3COONa·3H2O进行热重(TG)及差示扫描量热法(DSC)测试,分析了其热分解行为,并从热力学的角度对其脱水过程进行了讨论。结果表明,CH3COONa·3H2O的脱水过程可分为两个阶段,先失液态水形成CH3COONa溶液,再从溶液中脱出气态水,并且在加热过程中一直伴随着结晶水的蒸发逸出。用硅油覆盖的方法能很好地抑制低温时由于蒸汽压差异引起的CH3COONa·3H2O结晶水的不断蒸发逸出问题。

The thermal behavior of sodium acetate trihydrate（CH3COONa·3H2O） was studied by using thermogravimetry-differential scanning calorimetry（TG-DSC）. The results indicate that the thermal decomposition may proceed in two dehydration stages： the first is the loss of liquid water to form aqueous solution of sodium acetate, and the next is water vapor evolution from the solution. In addition, the crystal water of sodium acetate trihydrate evaporates all the time during the heating process. The evaporation at low temperature caused by water vapor pressure difference can be inhibited effectively through the silicone oil coverage method.