己二酸的结晶热力学研究

Study on Crystallization Thermodynamics of Adipic Acid

利用激光监测装置，采用合成法测定了己二酸在水、环己酮、环己醇、环己酮与环己醇混合溶剂（n（环已酮）：n（环己醇）分别为1：1，3：7，7：3）中的溶解度和超溶解度。己二酸在上述溶剂中的溶解度均随溶液温度升高而增大。己二酸在水中的溶解度随温度变化较大，当溶液温度由28℃左右升至78℃左右时，其溶解度可增大20倍。己二酸在环己酮、环己醇、环己酮与环己醇混合溶剂中的溶解度随温度变化较小，当溶液温度由28℃左右升至78℃左右时，其溶解度可增大4～10倍。用三次多项式关联己二酸溶解度与溶液温度的关系，溶解度的计算值与实验值最大相对误差为3．33％。己二酸存6种溶剂中的结晶介稳区宽度随温度的升高而减小，降低搅拌转速可使结晶介稳区宽度增大。己二酸在水中的结晶介稳区宽度最小，平均为572℃；存环已酮中的结晶介稳区宽度较大，平均可达14．90℃。

Solubility and supersolubility of adipic acid in water, cyclohexanone, cyclohexanol and their mixtures （ n （cyclohexanone） ： n （cyclohexanol） were 1 ： 1,3 ： 7, 7 ： 3 ） were measured by means of laser detection device. Solubilities of adipic acid in above-mentioned solvents increased with rising solution temperature. Solubility of adipic acid in water increased more rapidly than that in cyclohexanone, cyclohexanol and their mixtures in specified experimental temperature range. Solubility of adipic acid in water at 78 ℃ was approximately 20 times as much as that at 28 ℃, while its solubility in cyclohexanone, cyclohexanol and their mixtures was only 4 - 10 times in same temperature range. Using cubic equation,the experimental solubility data were successfully regressed with deviation of less than 3.33 %. Crystallization metastable zone width （ MSZW ） of adipic acid in above-mentioned six solvents narrowed with increase of solution temperature. Speeding up of stirring rate significantly narrowed crystallization MSZW. For dissolving of adipic acid in water a smallest average crystallization MSZW of 5.72 ℃ existed in comparing with its dissolving in other solvents and their mixtures, but for adipic acid dissolved in cyclohexanone there was a largest average crystallization MSZW of 14.90 ℃.