Thermodynamics of mixtures containing alkoxyethanols: Part XXVII. Predictions on isobaric thermal expansion coefficients, compressibilities and speeds of sound from the Flory theory

Abstract

The Flory model is applied to predict the isobaric expansion coefficients, α P, isentropic, κ S , and isothermal, κ T , compressibilities and speeds of sound, u, of the highly complex mixtures: hydroxyether + alkane, + dibutylether, + 1-butanol or + 2-methoxyethanol, 1-alkanol + alkane, and 1-alkanol + dibutylether. Predictions were obtained using the energetic parameter, χ 12, determined from values of excess enthalpies, H E, and from values of the excess isochoric internal energies, U V E , at equimolar composition. No meaningful differences exist between such predictions. Deviations between experimental and calculated values are lower than 2% for mixtures containing alkoxyethanols. Poorer results are obtained for 1-alkanol + dibutylether mixtures with deviations up to 5%. It is shown that predictions on α P, κ S , κ T , and u essentially depend on structural effects and not on the orientational effects present in the studied mixtures. Results are improved using χ 12 values fitted to molar excess volumes. In this case, deviations are similar to those obtained from semiempirical models as free length theory, collision factor theory, or Nomoto or Junjie equations.