Investigation on\nthe <i>pρT</i> Property\nof a Thymol/Decanoic Acid Eutectic Mixture

Due to the advantages of hydrophobility and low viscosity,\ntype\nV (deep) eutectic solvents have attracted more and more attention\nin recent years. However, the <i>p</i>-ρ-<i>T</i> property of the type V solvent is still scarce, which limited its\nfurther application. In this work, the high-pressure liquid densities\nof thymol/decanoic acid eutectic solvents at molar ratios of 2:3,\n1:1, and 3:2 were measured using a vibrating-tube densimeter. The\nstudied temperature range was from 293.15 to 363.15 K and the maximum\npressure reached was 40 MPa. The combined expanded uncertainty for\nthe present density measurement was estimated to be lower than 0.96\nkg·m<sup>–3</sup> at a confidence level of 95%. The experimental\nresults were correlated using a Tait-type equation and a multiparametric\nequation, respectively. The average absolute relative deviation between\nthe experimental data and calculated values is within 0.006% for the\nTait equation and 0.007% for the multiparametric equation. In addition,\nthe isothermal compression coefficient, isobaric thermal expansion\ncoefficient, and internal pressure of thymol/decanoic acid solvents\nwere calculated and discussed.