Equilibrium solubility, thermodynamic properties and Hansen solubility parameter of N-hydroxy-5-norbornene-2,3-dicarboximide in ethyl acetate + (2-methoxyethanol, methanol and 1,4-dioxane) at various temperatures

Solubility of N-hydroxy-5-norbornene-2,3-dicarboximide (HONB) in three mixed solvents of ethyl acetate + (2-methoxyethanol, methanol and 1,4-dioxane) was investigated within 278.15 K-323.15 K under 0.1 MPa. The solubility profiles indicated that the HONB solubility in measured solvents was proportional to the increment of test temperature and mass fraction of positive solvent (2-methoxyethanol, methanol or 1,4-dioxane). The mole fraction solubility of HONB varied significantly from 0.0115 in ethyl acetate + 1,4-dioxane (w(1) = 0.2066, 278.15 K) to 0.1788 in ethyl acetate + 2-methoxyethanol (w(1) = 0.7993, 323.15 K). Hansen solubility parameter was applied to reveal the miscibility and solubility order of HONB in mixed solvents, and the consequences indicated that solubility behaviors of HONB were the result of various solubility parameters comprehensive action. The measured HONB solubility employing laser monitoring technique was correlated with four activity coefficient models (Three-Suffix Margules, NRTL, UNIQUAC and Wilson) in combination with a semi-empirical model (Modified Apelblat). The smallest average values of average relative deviation (ARD) and root-mean square deviation (104 RMSD) were obtained from Wilson (0.66%) and Modified Apelblat model (6.02), verifying that these two models provided more satisfactory agreement and correlation than other three models. Furthermore, the thermodynamic parameters (Delta H-mix, Delta(mix)G and Delta S-mix) of the mixing process in different solvents were computed based on measured solubility values and equation parameters of Wilson model. The results demonstrated that the mixing process was entropy-driven and spontaneous. These solubility data and thermodynamic parameters could not merely extend database of HONB, but provide basic guidance for optimizing crystallization and purification process. (C) 2020 Elsevier B.V. All rights reserved.