Measurement and Correlation of Solubilities of Isophthalic Acid and m-Toluic Acid in Different Organic Solvents from 287.65 to 347.45 K

In this study, the solubilities of isophthalic acid (IPA) in N-methylformamide (NMFM), N-methylformanilide (NMFL), propanoic acid (PA), sulfolane, and dimethyl sulfoxide (DMSO) and m-toluic acid (m-TA) in acetone, cyclohexanone (CYC), 1-methyl-2-pyrrolidinone, NMFM, NMFL, N,N-dimethylformamide, PA, sulfolane, and DMSO were determined by the dynamic laser method at atmospheric pressure (101.2 kPa), and the solubility ratios between IPA and m-TA in different solvents were calculated. The temperature range of the experiment was between 290.15 and 348.15 K, in which the solubilities of IPA and m-TA in selected solvents were positively correlated with temperature. The maximum ratio between the mole fraction of solubilities of m-TA and IPA was in CYC and ranged from 68 to 84 for the temperature range under study. The experimental data were correlated by the Apelblat model, the Buchowski–Ksiazczak λh model, and the modified nonrandom two-liquid (NRTL) activity coefficient model.