甲苯、苯甲醇(醛/酸)在1-乙基-3-甲基咪唑四氟硼酸盐中溶解度的测定

采用浊点法和综合法分别测定了甲苯、苯甲醇和苯甲醛(299.2～338.2 K)、苯甲酸(313.2～343.2 K)在1-乙基-3-甲基咪唑四氟硼酸盐(emim]BF_4)中的溶解度。实验结果表明,在313.2～343.2 K内,苯甲酸在emim]BF_4中的溶解度远远大于其他组分的溶解度,在高于313 2 K时,摩尔分数大于28%;各组分溶解度均随温度的升高而增加,甲苯和苯甲醇具有相近的溶解度和随温度的变化趋势;在299.2～318 2 K内,苯甲醛的溶解度大于甲苯和苯甲醇的溶解度。关联结果表明,由相分裂条件得到的关联式能很好地拟合甲苯、苯甲醇和苯甲醛在emim]BF_4中的溶解度,其平均相对偏差分别为7.23%,3.81%,1 16%;经验方程、理想溶液模型和λh方程均能较好地关联苯甲酸在emim]BF_4中的溶解度,其平均相对偏差分别为0.42%,0.40%,1.91%。

Measurement of Solubilities of Toluene, Benzyl Alcohol, Benzaldehyde and Benzoic Acid in 1-Ethyl-3-Methylimidazolium Tetrafluoroborate

Solubilities of toluene, benzyl alcohol and benzaldehyde in ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate(emim]BF_4) were measured by cloud point method in temperature range of 299.2-338.2 K. Solubility of benzoic acid was measured by synthetic method in temperature range of 313.2-343.2 K. In this range,solubility of benzoic acid was the greatest and its mole fraction was greater than 28% when temperature was higher than 313.2 K. Solubilitiy of each solute increased with rising of temperature. Solubilities of toluene and benzyl alcohol were similar and so were their trends of changing with temperature. From 299.2 to 318.2 K, solubility of benzaldehyde was greater than these of toluene and benzyl alcohol. A correlation based on phase splitting fit the solubilities well. Average relative deviation(RD) was 7.23%, 3.81% and 1.16% for toluene, benzyl alcohol and benzaldehyde respectively. Empirical equation, ideal solution model and λh equation all fit solubility data of benzoic acid satisfactorily, and RDs were 0.42%, 0.40% and 1.91%, respectively.