Solubility Determination and Correlation for Bis(2-hydroxyethyl) Terephthalate (BHET) in Four Binary Solvents from 283.15 to 323.15 K
Peiquan Yuan, Baoshu Liu, Qiuju Li, Hua Sun
Abstract
The laser monitoring observation technique was used to study the solid–liquid equilibrium solubility data of bis(2-hydroxyethyl) terephthalate (BHET) in four binary mixed solvents (methanol + water, ethanol + water, ethylene glycol + water, and acetone + water) from 283.15 to 323.15 K at normal atmospheric pressure. Five thermodynamic models (the Apelblat model, the λh model, the Jouyban–Acree model, the Wilson model, and the NRTL model) were selected to correlate the experimental data. Based on the correlation index and the root-mean-square deviation, the Apelblat model and λh model were more suitable for fitting the BHET solubility data. According to the obtained Wilson model parameters, the thermodynamic properties during the dissolution of BHET were calculated. The results showed that the dissolution process of BHET in all mixed solvents was spontaneous.