화학공학소재연구정보센터
Canadian Journal of Chemical Engineering, Vol.82, No.2, 335-342, 2004
Measurement and prediction of the solubility of stearic acid polymorphs by the UNIQUAC equation
The solubility of stearic acid polymorphs B and C in methanol, 2-butanone, decane and hexane was measured using a precise gravimetric method. Stearic acid is a molecule with 18 carbons that is highly nonideal in solutions and experimental data show strong deviations from the solubility prediction for ideal systems. It is soluble in both polar and nonpolar organic solvents. From experimental solubility, data the solvent mediated polymorphic transition temperature was found around 30degreesC. From thermal analysis, temperature and heat of transition from form B to form C and also heat of fusion of form C were found to be 49degreesC, 20 J/g and 240 J/g, respectively. From experimental solubility data the binary parameters of the universal quasi-chemical (UNIQUAC) model, for stearic acid were calculated. The UNIQUAC solubility predictions compared very closely with the experimental data.