Solubility Determination and Thermodynamic Analysis of 2,4-Dichlorobenzoic Acid in 10 Pure Solvents and Three Binary Solvents at 273.15-318.15 K

2,4-Dichlorobenzoic acid (2,4-DCBA) plays a pivotal role in the synthesis of drugs and materials. Its solubility was meticulously determined using a static equilibrium method in conjunction with HPLC, across 10 individual solvents and three solvent mixtures. It can be found that 2,4-DCBA exhibited high solubility in alcohol solvents. Notably, in the acetone-acetonitrile system, solubility rose markedly with an increase in the positive solvent's fraction. In the methanol, ethanol, and acetonitrile mixtures, the solubility of 2,4-DCBA peaked when the positive solvent's molar fraction reached 0.8, suggesting that binary solvents can outperform single solvents in terms of dissolution. XRD and TG-DSC confirmed that 2,4-DCBA did not decompose, and its crystal structure did not change significantly during the experiment. The improved Apelblat model and lambda h model were used to fit and analyze the solubility data in a single pure solvent, and the CNIBS/R-K model, Jouyban-Acree model, and Sun model were used to process the solubility data in a binary solvent system. The reliability of the fitting results was confirmed by calculating the RAD and RMSD values of the thermodynamic models. Ultimately, the research utilized the KAT-LSER model to examine the impact of solvent characteristics on the solubility of 2,4-DCBA in individual solvents.