物理化学学报 >> 2010, Vol. 26 >> Issue (06): 1468-1472.doi: 10.3866/PKU.WHXB20100637

热力学、热化学和溶液化学 上一篇    下一篇

1-丁基-3-甲基咪唑四氟硼酸盐的热稳定性、平衡蒸汽压和标准蒸发焓

梁蕊, 杨美荣, 周庆祥   

  1. 河南师范大学化学与环境科学学院, 河南 新乡 453007
  • 收稿日期:2010-02-01 修回日期:2010-04-02 发布日期:2010-05-28
  • 通讯作者: 梁蕊 E-mail:yhb.lr@126.com

Thermal Stability, Equilibrium Vapor Pressure and Standard Enthalpy of Vaporization of 1-Butyl-3-methylimidazolium Tetrafluoroborate

LIANG Rui, YANG Mei-Rong, ZHOU Qing-Xiang   

  1. School of Chemistry and Environmental Sciences, Henan Normal University, Xinxiang 453007, Henan Province, P. R. China
  • Received:2010-02-01 Revised:2010-04-02 Published:2010-05-28
  • Contact: LIANG Rui E-mail:yhb.lr@126.com

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摘要：

利用非等温、等温热重分析(TG)法, 研究了高纯氮气气氛下1-丁基-3-甲基咪唑四氟硼酸盐([bmim][BF4])离子液体的热稳定性、平衡蒸汽压和标准蒸发焓. 非等温热重(TG)曲线表明[bmim][BF4]的初始分解温度(Tonset)和最大分解速率对应的温度(Tm)分别为697 和734 K. 然而长期等温TGA研究表明, [bmim][BF4]的最高可使用温度约为513 K. 另外, 利用基于TG的蒸发技术研究了[bmim][BF4]的平衡蒸汽压(pe)与温度的关系并计算了标准蒸发焓. 在503-543 K温度范围内, 离子液体[bmim][BF4]的pe和温度的关系是: lgpe=(16±1)+(-6.85±0.25)×103/T. [bmim][BF4]的标准蒸发焓为(131±5) kJ·mol-1.

关键词: 离子液体, 1-丁基-3-甲基咪唑四氟硼酸盐, 热稳定性, 平衡蒸汽压, 标准蒸发焓

Abstract:

The thermal stability, equilibrium vapor pressure, and standard enthalpy of vaporization of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) ion liquid were investigated using both non-isothermal and isothermal thermogravimetric analysis (TGA) under high purity nitrogen as a carrier gas. The non-isothermal thermogravimetric (TG) curve showed that the onset and peak decomposition temperatures were 697 and 734 K, respectively. However, long-term isothermal TGA studies revealed that the highest application temperature for [bmim][BF4] was 513 K. Moreover, the temperature dependence of the equilibrium vapor pressure and the standard enthalpy of vaporization of [bmim][BF4] were also investigated by TG-based transpiration. In the temperature range of 503-543 K, the relationship between the equilibrium vapor pressure (pe) of [bmim][BF4] and temperature was lgpe=(16±1)+(-6.85±0.25)×103/T. The standard enthalpy of vaporization (△vapHΘ) of [bmim][BF4] was found to be (131±5) kJ·mol-1.

Key words: Ionic liquid, 1-Butyl-3-methylimidazoliumtetrafluoroborate, Thermal stability, Equilibrium vapor pressure, Standard enthalpy of vaporization