Solubility of Dimethyl Terephthalate and Monomethyl Terephthalate in the Methanol Aqueous Solution and Its Application To Recycle Monomethyl Terephthalate from Crude Dimethyl Terephthalate

Abstract

The solubilities of dimethyl terephthalate (DMT) and monomethyl terephthalate (MMT) in methanol aqueous solutions were determined in the temperature range of 280−336 K. The solute-free mass fractions of methanol extended from 0.3 to 1.0. Both the solubilities of DMT and MMT in aqueous methanol solution increase with the temperature and the addition of methanol. The experimental data were correlated with the Wilson and the NRTL models. The root-mean-square deviations for the system of (DMT + methanol + water) were 1.30 and 1.33 K calculated by the Wilson and the NRTL models, respectively, while for the system of (MMT + methanol + water), the root-mean-square deviations were 0.55 and 0.82 K. The melting points and the enthalpy of fusion of DMT and MMT were detected by the differential scanning calorimetry (DSC). A simple purification and recycling process was designed to separate MMT from the esterification reaction product according to the solubility difference between DMT and MMT.

Measurement and correlation of solubility of 4-chloro-2,5-dimethoxynitrobenzene and 4-chloro-2,5-dimethoxyaniline in methanol, ethanol, xylene and toluene

“…The Wilson and the NRTL models, which have been successfully used to describe the (solid + liquid) equilibrium (SLE) [9][10][11][12][13][14], were employed to correlate the experimental results. The interaction parameters of the models were obtained.…”

Solubility of 4-Chloro-2,5-dimethoxynitrobenzene, 4-Chloro-2,5-dimethoxyaniline, and 2,5-Dimethoxyaniline in Binary and Pure Solvents: Determination and Modeling

“…The solubility data of CDMA are processed in the same way. The model parameters of the Wilson and the NRTL models in methanol–water and ethanol–water solvent mixtures are listed in Tables and , where the parameters of methanol with water and ethanol with water are reported by Zhang and Chen . The RMSD which is taken as the objective function are listed in Table .…”

“…In this work, the solubilities of CDMA and CDMB in methanol–water and ethanol–water solvent mixtures, and the solubilities of CDMA, CDMB, and DMAn in 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, and diethylene glycol had been measured by a dynamic method over the temperature range from 277 to 340 K at atmosphere pressure. The experimental data in methanol–water and ethanol–water solvent mixtures were correlated with the Wilson and the NRTL models, and the data in pure organic solvents were correlated with the Wilson, the NRTL, the modified Apelblat, and the λ h models, which have been successfully used to describe the solid–liquid equilibrium (SLE). − According to the solubility values, the preferred solvent for iron powder reduction and the solvent for the recrystallization process of CDMA were suggested.…”

Microwave Accelerated Methanolysis of Poly(ethylene terephthalate)

“…The solid products (and unreacted PET) are transferred into another vial by washing with 20-25 mL water and chilled 4 °C to encourage the complete precipitation. 20 The solids were collected by filtration and dried. For analysis of these solids, chloroform was used to dissolve DMT etc., leaving the unreacted PET undissolved.…”