Measurement and correlation of solubility of trimethylolethane in different pure solvents and binary mixtures

The solubilities of trimethylolethane in butanol,methyl acetate,ethyl acetate as well as in mixed solvents of(methanol+ethyl acetate) and(ethanol+ethyl acetate) were measured with the gravimetric method in the temperature range from 283.15 K to 318.15 K under atmosphere pressure.The experiment results showed that the solubility of trimethylolethane increased with the temperature,or along with the concentration of methanol or ethanol in the solvents of(methanol+ethyl acetate) and(ethanol + ethyl acetate).In addition,the experiment values were correlated by the van't Hoff equation,Modi fied Apelblat Equation,λh Equation,CNIBS/R-K equation and Jouyban–Acree Model.The Modi fied Apelblat Equation provided the best fitting results of the solubility data of TME in the pure solvents while the CNIBS/R-K model showed the best estimation of the solubility in the binary solvent mixtures.Furthermore,the density functional theory(DFT) calculations showed that solubility in different solvents related to the strength of the interaction between the trimethylolethane and the solvent molecules.Finally,the standard molar enthalpy and molar entropy of trimethylolethane during the dissolving process was also calculated by Modi fied Apelblat equation in this work.

枞酸在四种醇类溶剂中的溶解度测定与关联

采用激光监视技术判定平衡点,由动态法测定了枞酸在甲醇、无水乙醇、正丙醇、正丁醇中的固液溶解度,实验测定温度由282 K至320 K,用λh方程、Wilson方程、简化方程分别对溶解度实验数据进行关联。结果表明,枞酸在四种醇类溶剂中的溶解度均随温度的升高而增大,且在不同溶剂中枞酸溶解度有较大的差异,大小顺序为:正丁醇>正丙醇>无水乙醇>甲醇。枞酸在四种醇类溶剂中的溶解度实验数据用λh方程、Wilson方程和简化方程关联的平均相对误差最大值分别为1.43%,1.19%和1.24%。上述结果可为枞酸结晶过程溶剂选择提供基础热力学数据。

丁二酸在五种有机溶剂中溶解度测定及关联

采用激光监视技术由动态法测定了丁二酸在环己醇、环己酮、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺和冰醋酸中的固液平衡数据,实验测定温度由室温至近353K,并分别用λh方程和NRTL方程对溶解度实验数据进行关联。根据实验数据可以看出丁二酸在五种溶剂中的溶解度均随温度的增加而增大,并且在不同溶剂中丁二酸的溶解度有较大差异。溶解度实验数据用λh方程关联和NRTL方程模型拟合结果的最大平均相对误差分别为3.98%和5.13%。结果表明λh方程模型和NRTL方程模型均能很好地关联丁二酸在五种有机溶剂中的溶解度数据。

乙醇-水溶剂中阿斯巴甜溶解度及介稳区的研究

在5~60℃温度范围内,研究阿斯巴甜在不同比例的乙醇-水混合溶剂中的溶解与超溶解特性,得到了阿斯巴甜的结晶介稳区,并推算出表观成核级数m,给出了成核速率方程。采用λh方程关联6个体系的溶解度数据,并考察温度、溶剂组成、降温速率以及搅拌速率对结晶介稳区的影响。结果表明:阿斯巴甜的溶解度随着温度和乙醇质量分数的增加而增加,当质量比w=0.5时出现溶解度的协同效应;随着温度和乙醇质量分数的增加,阿斯巴甜结晶介稳区宽度减小;在相同条件下,搅拌速率的降低和降温速率的升高均会增大阿斯巴甜结晶介稳区的宽度。