Solid-Liquid Equilibrium of Terephthalic Acid in Several Solvents

Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work, solid-liquid equilibriums of terephthalic acid in four solvents, N.N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is most suitable for description of the solid-liquid equilibrium containing PTA.