Solubility Determination and Thermodynamic Modeling of Buprofezin in Different Solvents and Mixing Properties of Solutions

In this work, the equilibrium solubility of buprofezin in different pure solvents was determined. The mole solubility of buprofezin in these studied pure solvents increased with increasing temperature. The solubility data decreased according to the following order: toluene > ethyl acetate > DMF > acetone > 1-octanol > 1-butanol > n-propanol > acetonitrile > isopropanol > ethanol > methanol > water. The results were correlated with four thermodynamic models (the modified Apelblat equation, λh equation, NRTL model, and Wilson model), and the values of root-mean-square deviation (RMSD) and relative average deviation (RAD) are no more than 27.26 × 10–4 and 2.76%, respectively. Due to the maximum values of RAD and RMSD were 1.58% and 3.77 × 10–4 in modified Apelblat equation, which indicate that it is a suitable model to describe the results. Besides, the mixing Gibbs energy, mixing enthalpy, and mixing entropy were computed. The values of Δmix G are negative in this experiment; therefore, the dissolution process is a spontaneous and favorable process, and the Δmix S are all positive, which indicate the dissolving process is entropy favorable as well.