Physico-Chemical Properties of Binary Liquid Mixtures of n-Hexane + Acrylic Esters (C₄, C₅, C₆, C₇) at Different Temperatures

Abstract

Densities ρ, ultrasonic speeds u, and refractive indices n for pure n-hexane, methylacrylate (MA), ethylacrylate (EA), ethylmethacrylate (EMA), butylacrylate (BA), and of their 36 binary mixtures over the entire composition range were measured at 298.15, 303.15, 308.15, and 313.15 K. Using these data, the excess molar volumes, V^E, deviations in isentropic compressibilities, Δk_s, deviations in molar refractions, ΔR_m, and deviations in internal pressure, ΔP_i, were calculated for the mixtures at given temperatures. Apparent molar volumes, V_ϕ,2, and apparent molar compressibilities, K_ϕ,2, of acrylic esters in n-hexane were also calculated. Partial molar volumes, , and partial molar isentropic compressibilities, , at infinite dilution were estimated. Moreover, the optical property and partial molar refraction, , of the systems at infinite dilution were examined. The variations of these parameters and of the optical property suggest that the strength of interactions in these mixtures follow the sequence: MA < EA < EMA < BA.

Keywords:

• Density
• Liquid mixtures
• Molecular interactions
• Organic solvents
• Refractive index
• Ultrasonic speed