Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

(Solid + liquid) phase diagrams have been determined for (1-octanol or 1-nonanol or 1-decanol or 1-undecanol + octylamine) mixtures. Solid addition compounds form with the empirical formulas C8H17OH?C8H19N, C9H19OH?C8H19N, C10H21OH?C8H19N, and C11H23OH?C8H19N. All are congruently melting compounds. Compound formation is attributed to a strong A-B interaction. The excess molar volumes have been determined for an alcohol (1-octanol, 1-nonanol, 1-decanol, or 1-undecanol) + octylamine at 298.15 K and atmospheric pressure. The systems exhibit very large negative molar excess volumes and molar excess enthalpies. The curves are nearly symmetrical. Strong cross-association between hydroxyl and amine groups (OH? ? ?NH2) is a dominant effect, and it causes high negative values of excess volume and excess enthalpy and a 1:1 congruently melting solid compound at lower temperatures. Our experimental data of excess volume and the literature data of Hex were treated in terms of the ERAS, DISQUAC, and modified UNIFAC models. The ERAS model consistently describes excess volume values and excess molar enthalpies of the studied mixtures.