磷酸三钠十二水合物脱水过程的研究

摘要

通过热重分析（TG）、差热分析（DSC）、X射线粉末衍射（PXRD）和扫描电镜（SEM）研究了磷酸三钠十二水合物（Na₃PO₄·12H₂O）在303.15~413.15 K温度范围内的脱水过程。研究结果发现，磷酸三钠十二水合物在303.15~393.15 K温度范围内逐渐脱去11个结晶水，且脱水过程包含多步反应。分别通过Ozawa方程和Friedman方程计算其在不同脱水率下的活化能，二者得到结果一致性较好。整个脱水过程可以分为4个阶段，其脱水机理有所不同。不同温度下脱水产物的PXRD和SEM图表明其属于通道型包容水合物，在脱水过程中晶格结构发生了变化。

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	张弓
	党乐平
	卫宏远

关键词：磷酸三钠十二水合物；脱水；热重/差热分析； X射线粉末衍射；扫描电镜

Abstract：

The dehydration process of trisodium phosphate dodecahydrate (Na₃PO₄·12H₂O) from 303.15 K to 413.15 K was investigated by using thermogravimetry (TG), differential scanning calorimetry (DSC), power X-ray diffraction (PXRD) and scanning electron micrograph (SEM). It was found that 11 mol crystal water of trisodium phosphate dodecahydrate was dehydrated from 303.15 K to 393.15 K and the process included multi-step reactions. Activation energies of dehydration at different dehydration rate were calculated by Ozawa equation and Friedman equation, respectively and a good identity of results was reached. The process of dehydration consisted of four steps, which were different in dehydration mechanism. The PXRD and SEM of dehydration products at different temperature showed that it was channel-type inclusion hydrate and crystal structure has transformed during the process of dehydration.

Keywords： trisodium phosphate dodecahydrate； dehydration； TG/DSC； PXRD； SEM

Received 2016-04-05;

Corresponding Authors: 党乐平,E-mail:dangleping@tju.edu.cn Email: dangleping@tju.edu.cn

About author: 张弓(1991-),男,硕士研究生,现从事工业结晶与分离过程方面的研究。

引用本文:

张弓, 党乐平, 卫宏远.磷酸三钠十二水合物脱水过程的研究[J]. 化学工业与工程, 2018,35(4): 46-51,65

Zhang Gong, Dang Leping, Wei Hongyuan.Investigations on Dehydration Process of Trisodium Phosphate Dodecahydrate[J]. Chemcial Industry and Engineering, 2018,35(4): 46-51,65

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