Isothermal vapour/liquid equilibria of binary mixtures with dibutyl ether at 298.15 K

A head-space gas chromatographic technique has been used to determine vapour/liquid equilibria at 298.15 K of binary mixtures of di-n-butyl ether plus an organic compound (hexane, octane, diethyl ether, tetrahydrofuran, propylamine, butylamine, propanone, cyclopentanone, methanol, butan-1-ol, acetonitrile). Excess molar Gibbs energies, G(E), for the systems investigated have been obtained by a least-squares treatment of equilibrium data. Mixtures with hexane, octane and diethyl ether revealed an almost ideal behaviour. Other systems showed positive deviations, which increase with the polarity of the second component. Dibutyl ether+butanol and +cyclopentanone revealed the formation of azeotropic compositions. The Kirkwood-Buff integrals over the entire composition range have been calculated from the composition dependence of G(E), and briefly discussed.