Thermodynamics of Mixtures Containing Organic Carbonates. 14. Excess Molar Gibbs Energies for 1-Hexanol + Dimethyl or Diethyl Carbonate Systems at 353.15 and 363.15 K. Comparison with ERAS Results

Abstract

Vapor−liquid equilibria (P−x measurements) at 353.15 and 363.15 K for 1-hexanol + dimethyl carbonate or + diethyl carbonate are determined by an ebullometric method. The data are reduced using Barker's method. All of the systems present positive deviations from Raoult's law. Mixtures are studied in the framework of the ERAS model assuming that 1-alkanols are the only self-associated compounds in the investigated solutions. According to the high HE (excess molar enthalpy) values of 1-alkanol + linear organic carbonate systems, the model predicts a weak cross association between the mixture components. The deviations between the experimental GE (excess molar Gibbs energy) and HE values and the ERAS results can be ascribed to the existence of strong polar interactions between carbonate molecules, not described properly by the model.