In this work, the solubility of 1,3-dimethylurea form I (DMUI) in seven solvents including water, 2-butanol, 2-propanol, acetone, acetonitrile, ethyl acetate and butyl acetate were measured by a synthetic method at a temperature range from (288.15 to 328.15) K at atmospheric pressure. For the temperature range investigated, the solubility of DMUI in the selected solvents increased with increasing temperature. Results of these measurements were well-correlated with the modified Apelblat equation, λh equation, van’t Hoff equation and Wilson model. Besides, the thermodynamic data ( i.e. , Gibbs energy, enthalpy, and entropy of mixing) were calculated by using the Wilson model. The chemical potential, solvation free energy and interaction enthalpy of DMU in solution were calculated by COSMO-RS model. This model was also applied to predict DMU solubility which showed good agreement with the experimental values.
In this work, solubility data of 1,3-dimethylurea (DMU) in methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol were measured by synthetic method from T = 288.15 to 328.15 K at ordinary pressure. It turned out that the solubility data increased as temperature and solvent polarity increased. The molecular interactions in solution have been studied by the linear energy relationship. Furthermore, based on two thermodynamic models (i.e., modified Apelblat and Wilson), the experimental results were fitted and analyzed. Finally, the thermodynamic properties of solution, including entropy, enthalpy, and Gibbs energy were calculated. These results indicate that in all selected solvents the dissolution behavior were endothermic, entropy-driven, and not spontaneous.