Binary mixtures of tributylamine with aromatics (toluene, ethylbenzene, o-xylene, m-xylene, p-xylene and nitrobenzene) were selected in order to investigate intermolecular interactions by calculation of their excess molar volume V-m(E), from density measurements. Thermal expansion coefficients alpha(p), and their excess values of alpha(E), were obtained from the density data. The V-m(E) values were positive for all the mixtures except for the (tributylamine + nitrobenzene) binary mixture over the entire range of composition and lower temperatures and become more positive with rising temperature. At high temperatures, sigmoidal behavior was observed for the mixture of (tributylamine + o-xylene). The mixture of (tributylamine + nitrobenzene) shows negative values for V-m(E) and become more negative with increasing temperature. The experimental data were correlated to Redlich-Kister equation. In order to characterize the V-m(E) values, the extended real associated solution (ERAS) model was applied at different temperatures. (C) 2011 Elsevier Ltd. All rights reserved.