Determination of Hildebrand solubility parameter of pure 1-alkanols up to high pressures

Abstract

An extended approach to determine Hildebrand solubility parameter (HISP) of pure 1-alkanols by precise calculation of the isothermal compressibility coefficient and heat capacities is proposed. The approach is introduced during its implementation for four pure polar 1-alkanols, namely 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol. Having described the approach, the prediction ability of that is compared with the previous methods for calculation of the properties. Comparisons show that for all the three mentioned properties, the proposed approach provides significantly better predictions. The mean absolute error for prediction of the isothermal compressibility coefficient, isobaric heat capacity, and HISP by the proposed approach are 1.77, 1.32, and 0.17% (for 1-heptanol), 1.54, 1.11, and 0.18% (for 1-octanol), 2.90, 0.97, and 0.28% (for 1-nonanol), and 1.39, 1.61, and 0.39% (for 1-decanol), respectively. In addition to checking the accuracy of the proposed approach, to investigate the impacts of temperature and pressure as two key parameters on HISP of 1-alkanols, sensitivity analyses are conducted. The results of sensitivity analyses show that same as the non-polar substances, in the case of polar compounds, increase in pressure leads to an increase in HISP. Furthermore, when temperature does not change, HISP approaches a constant value at high pressures. Moreover, the relationship between temperature and HISP is linear.