Pressure effects on the thermodynamic properties of (n-hexane plus 1-hexanol) binary mixtures

On the basis of pressure-scanning measurements of isobaric thermal expansivities, alpha(p)(p,T), of n-hexane, 1-hexanol and their binary mixtures at 0.1088, 0.2735, 0.4965, 0.6034, and 0.7453 hexanol molar fractions, and of isotherms of molar volumes at reference temperatures, the pressure derivatives of excess thermodynamic functions have been derived over the pressure range up to 400 MPa and at temperatures from 303 to 503 K. The obtained results presented in the form of isobars-isopleths clearly demonstrate the shifting, from positive to negative, of the pressure effects on thermodynamic functions when composition, temperature or pressure varies. The observed phenomena are discussed in terms of association equilibria in this system. (C) 1997 Elsevier Science B.V.