文章采用溶解平衡法,在273-333K温度范围内,测定了N,N-二(2-羟丙基)哌嗪(HPP)在水、甲醇、乙醇、异丙醇、正丁醇、正己烷、环己烷、甲苯、苯、乙醇-水混合溶剂中的溶解度。在不同溶剂中,HPP溶解度均随温度升高而增大。相同温度下HPP的溶解度从大到小依次为甲醇、乙醇、正丁醇、水、异丙醇、苯、甲苯、环己烷、正己烷;在乙醇一水体系中的溶解度从大到小依次为33%乙醇、100%乙醇、66%乙醇、50%乙醇、水。分别采用Apelblat方程、理想溶解度方程对溶解度数据进行了关联,并获得相关关联模型的参数。利用Van’t Hoff方程估算了溶解过程的溶解焓和熵,同时测定了HPP在乙醇中的介稳区。结果表明,随着温度和搅拌速率的降低,HPP结晶介稳区的宽度增大。
The solubility of 1, 4-bis (2-hydroxypropyl)-piperazine (HPP) in different solvents such as water, methanol, ethanol, isopropanol, n-butyl alcohol, n-hexane, cyclohexane, toluene, benzene and ethanol-water mixture was determined through dissolution equilibrium method at the temperature range from 273 K to 333 K. The results indicated that the solubility in all the solvents increased with temperature. The solubility of HPP in solute molar fraction followed the order of methanol〉ethanol n-butyl alcohol〉 water〉isopropanol〉benzene〉 toluene〉 cyclohexane〉 n-hexane under the same temperature. For the water-ethanol mixture solvent, the solubility of HPP followed the order of 33 % ethanol〉100% ethanol〉66% ethanol〉50% ethanol〉water. The solubility data was correlated by using Apelblat equation and ideal solubility equation respectively, and the parameters for each model were obtained. The dissolution enthalpy and dissolution entropy were evaluated by applying Van't Hoff equation. And the metastable zone widths of the HPP ethanol solution at different temperatures and stirring rates were investigated. It was shown that the width of metastable zone increased with the decrease of temperature and stirring rate.