Determination and correlation of terephthaldialdehyde solubility in (ethanol, isopropanol, ethyl acetate, isopentanol) + N,N-dimethylformamide mixed solvents at temperatures from 273.15 K to 318.15 K

Abstract

In this work, the solubility of terephthaldialdehyde in mono-solvent of ethyl acetate and binary solvent mixtures of (ethanol+N,N-dimethylformamide), (isopropanol+N,N-dimethylformamide), (ethyl acetate+N,N-dimethylformamide) and (isopentanol+N,N-dimethylformamide) were investigated by the isothermal dissolution equilibrium method under 101.1kPa. This study was carried out at different mass fractions of ethanol, isopropanol, or isopentanol ranging from 0.1 to 0.9; and of ethyl acetate, from 0.1 to 1 at T=(273.15–318.15) K. For the solubility of each solvent mixture studied, the mole fraction solubility of terephthaldialdehyde in mixed solutions increased with increasing temperature and mass fraction of ethanol, isopropanol, ethyl acetate or isopentanol for the four systems of (ethanol+N,N-dimethylformamide), (isopropanol+N,N-dimethylformamide), (ethyl acetate+N,N-dimethylformamide) and (isopentanol+N,N-dimethylformamide). At the same temperature and mass fraction of ethanol, isopropanol, ethyl acetate or isopentanol, the mole fraction solubility of terephthaldialdehyde in (ethyl acetate+N,N-dimethylformamide) was greater than that in the other three systems. In addition, five models (Jouyban–Acree model, van’t Hoff–Acree model, modified Apelblat–Acree model, Sun model and CNIBS/R-K model) were employed to correlate the experimental solubility data. The Jouyban–Acree model gave best representation of the experimental solubility values. Furthermore, the standard molar enthalpy of terephthaldialdehyde dissolving in these mixed solvents (ΔsolHo) was calculated in this work, and the results showed that the dissolution process was endothermic.