Densities, excess molar volumes, speeds of sound, and isothermal compressibilities for 2-(2-hexyloxyethoxy)ethanol plus n-alkylamine at temperatures between 288.15 K and 308.15 K

The densities, rho, and the speeds of sound, u, for binary liquid mixtures containing 2-(2-hexyloxyethoxy)ethanol (C6E2) and n-butylamine (BA), dibutylamine (DBA), and tributylamine (TBA) have been measured as a function of composition using a vibrating tube densimeter and sound analyzer Anton-Paar model DSA-5000 at temperatures (288.15, 293.15, 298.15, 303.15, and 308.15) K and atmospheric pressure. The rho and u values were used to calculate excess molar volumes, V-m(E), and excess molar isentropic compressibility, K-S,m(E), respectively. The V-m(E) and K-S,m(E) values are shown to be negative for all the mixtures over the entire composition range. Both V-m(E) and K-S,m(E) become more negative for all the mixtures with the rise of temperature. The change of V-m(E) and K-S,m(E) with composition and temperature are discussed with a view to understand molecular interactions present in alkoxyethanol-alkylamine mixtures.