Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The present work mainly report the terephthalaldehydic acid solubility in aqueous solutions of methanol, ethanol, isopropanol and NMP, which was acheived through steady-state method covering a temperature range of (283.15 to 323.15) K under 101.1 kPa. The terephthalaldehydic acid solubility increased positively as the mass fraction of methanol (ethanol, isopropanol and NMP) increased for the investigated mixtures of methanol (ethanol, isopropanol and NMP) + water. At the same temperature and mass fraction of methanol (ethanol, isopropanol and NMP), the mole fraction terephthalaldehydic acid solubility was higher in (NMP + water) mixture than in the other three mixtures. The solid equilibrating with saturated liquor was indentified through X-ray power diffraction showing no crystal transition, polymorphic transformation or solvate formation. Three models such as the Van't Hoff-Jouyban-Acree, Jouyban-Acree and Apelblat-Jouyban-Acree were used here to correlate the obtained solubility data. The back-calculated values were in good agreement with the determined ones. The values of RAD and RMSD were, respectively, no greater than 3.63 % and 6.66x10-4. Preferential solvation of terephthalaldehydic acid in the four mixtures was analyzed by employing the method of inverse Kirkwood-Buff integrals. The preferential solvation parameter x1,3 by NMP (methanol, ethanol or isopropanol) (1) is positive within the composition range of 0.16 less than x1 less than 1 for NMP, 0.32 less than x1 less than 1 for methanol, 0.25 less than x1 less than 1 for ethanol and isopropanol. As can be speculated that in the regions, where terephthalaldehydic acid is preferentially solvated by NMP (methanol, ethanol or isopropanol), terephthalaldehydic acid is acting as a Lewis acid with NMP (methanol, ethanol or isopropanol) molecules.