Thermodynamics of (1-alkanol + linear monoether) systems

Densities, ρ, and speeds of sound, u, of systems formed by 1-heptanol, or 1-octanol, or 1-decanol and dibutylether have been measured at a temperature of (293.15, 298.15, and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyser Anton Paar model DSA-5000. The ρ and u values were used to calculate excess molar volumes, VE, and deviations from the ideal behaviour of the thermal expansion coefficient, Δαp and of the isentropic compressibilities, ΔκS. The available database on molar excess enthalpies, HE, and VE for (1-alkanol + linear monoether) systems was used to investigate interactional and structural effects in such mixtures. The enthalpy of the OH⋯O bonds is lower for methanol solutions, and for the remainder systems, it is practically independent of the mixture compounds. The VE variation with the chain length of the 1-alkanol points out the existence of structural effects for systems including longer 1-alkanols. The ERAS model is applied to the studied mixtures. ERAS represents quite accurately HE and VE data using parameters which consistently depend on the molecular structure.