采用热重(TG-DTA)、定压比热(Cp)和原位高温红外反射光谱等热分析手段研究了四方相KDP晶体室温至260℃之间的高温热行为.实验发现:KDP晶体在183℃附近并未发生四方相到单斜相的相变或发生脱水反应;且晶体于207 ～ 210℃左右开始分解,随温度上升,分解过程分为三个阶段.第一个分解阶段出现P2O72-基团的吸收峰,意味着第一阶段的分解朝着K4P2O7的方向进行;第二阶段是第一阶段产生的中间态产物继续分解的过程;第三个分解阶段为前两个过程的继续分解,最终KDP完全分解为KPO3.通过Kissinger法,根据热重数据计算了KDP在260℃前两个明显的分解过程的动力学参数,其热脱水活化能分别为101.7 J·mol-1和112.4 J·mol-1.
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