LAUSR

Abstract The equilibrium solubility and thermodynamic properties of N-hydroxyphthalimide (NHPI) in n-propanol, 2-methoxyethanol, 1,4-dioxane, n-propyl acetate, ethanol, acetonitrile, methyl acetate, 2-ethoxyethanol, acetone, methanol and ethyl acetate were reported. Solubility determinations were performed through laser monitoring method in the temperature range of (278.15–323.15) K (except 1,4-dioxane at 288.15–323.15 K). It is found that the mole fraction solubility of NHPI increases apparently with augmented experimental temperature. The measured data is observed highest in 2-methoxyethanol (0.3807), followed by 2-ethoxyethanol (0.2601), 1,4-dioxane (0.2307), acetone (0.1260), methanol (0.06572), ethanol (0.06138), methyl acetate (0.05282), n-propanol (0.04670), acetonitrile (0.04141), ethyl acetate (0.03992), n-propyl acetate (0.03286) at “T = 298.15 K”. Various properties of materials including solvent polarity and Hansen solubility parameter of NHPI as well as selected solvents were summarized to analyze the solubility order of NHPI in studied solvents. The analysis consequence shows that solubility of NHPI in selected solvents is affected by multiple factors. Moreover, all recorded solubility was regressed by the modified Apleblat equation, Wilson model, NRTL model and NRTL-SAC model, attaining the average 100ARD (average relative deviation) value lower than 1.200 and average 104RMSD (root-mean square deviation) value lower than 1.550. Furthermore, analysis of thermodynamic properties indicates that the mixing and dissolution of NHPI in all considered cases are entropy-driven and spontaneous processes.