Abstract:

Polyalcohols exhibit crystalline transformation which reversibly absorb and release a large amount of heat and can be used for thermal energy storage.The experimental phase diagram of binary system, pentaerythritol-2-amino-2-methyl-1,3-propanediol (PE-AMP), was established by three kinds of techniques: differential thermal analysis(DTA) method, X-ray diffraction and IR spectra at various temperatures.The phase diagram was characterized by three invariant equilibria: a peritectoid at 86℃, and, a eutectoid at 143℃, and a peritectic at 176℃.X-ray diffraction was used to determine the phase structure of the binary system at different temperature.The temperature of solid-solid phase transition for polyalcohols measured by the DTA method was consistent with the results of IR,in which the —OH stretching absorptions in infrared spectra of two polyalcohols and their binary system shifted to a higher wavenumber. The miscibility of the system was discussed on the basis of intermolecular interactions between ordered low-temperature phase and orientationally disordered high-temperature phase.

Key words:

季戊四醇, 2-氨基-2-甲基-1,3-丙二醇, 二元体系, 相图

摘要：

多元醇在固-固相变时能够可逆地吸收和释放大量的热而被用于贮热材料。为了选择适宜的贮热材料，对季戊四醇(PE)和2-氨基-2-甲基-1,3-丙二醇(AMP) 两种多元醇利用差热分析 (DTA)、X射线衍射和变温红外光谱3种技术构筑了二元体系相图。由所得PE-AMP二元相图可知，在一定的组成范围内相图中存在3个相平衡温度：低转析温度86℃、低共析温度143℃和转熔温度176℃。X射线衍射确定了二元体系不同温度下的相态。变温红外光谱测得多元醇—OH特征吸收峰位移发生突跃的温度区间恰好与体系各自DSC测得的相转变温度相吻合，多元醇的晶体结构、分子的大小是影响二元体系不同相态间互溶度的重要因素。

关键词:

季戊四醇, 2-氨基-2-甲基-1,3-丙二醇, 二元体系, 相图