Thermodynamics of 1,3-Dimethylurea in Eight Alcohols

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.