Densities, Viscosities, and Refractive Indices of Binary Mixtures Containing n-Hexane + Components of Pine Resins and Essential Oils at 298.15 K

Densities, ρ, viscosities, η, and refractive indices, n D, of binary mixtures containing n -hexane + α-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), + β-pinene (6,6-dimethyl-2-methylene bicyclo[3.1.1]heptane), + p -cymene (1-methyl-4-[1-methylethyl]benzene), + ( S )-(−)-limonene [(−)-1-methyl-4-(1-methylethenyl)cyclohexene], + 1,8-cineole (1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane), and + linalool (3,7-dimethyl-1,6-octadien-3-ol) were determined at 298.15 K and at atmospheric pressure using a digital density meter, a Schott viscosity measuring system, and an Abbe refractometer, respectively. The excess molar volumes,, deviations in viscosities, Δη, and deviations in molar refractions, Δ R, calculated from experimental measurements, are always negative, with the exception of the curve referring to the hexane + linalool mixture, which shows an inversion of sign. Results were fitted to the Redlich−Kister polynomial and qualitatively discussed in terms of molecular interactions. The McAllister multibody interaction model was used to correlate the kinematic viscosities of liquid mixtures with mole fractions.