ESTIMATION OF DISQUAC INTERCHANGE ENERGY PARAMETERS FOR N-ALKYLAMINE PLUS BENZENE MIXTURES

The experimental literature data on vapor-liquid equilibria (VLE), exc ess molar Gibbs energies (G(m)(E)), excess molar enthalpies (H-m(E)) a nd activity coefficients of n-alkylamine + benzene mixtures are interp reted in terms of the DISQUAC group contribution model. The systems ar e characterized by three types of groups or contact surfaces: aliphati c (a), benzene (b) and amine (n). The interchange energies of the alip hatic/benzene and aliphatic/amine contacts were determined independent ly from the study of benzene + n-alkane and n-alkylamine + n-alkane sy stems, respectively. The interchange energies of the benzene/amine con tact were calculated in this work from experimental G(m)(E) and H-m(E) values. In view of the importance of the NH2-pi interaction, we have kept constant a quasichemical coefficient for the benzene-amine contac t and we have only varied the dispersive coefficients with the length of the n-alkylamine. The model reproduces quite well the experimental data.