Volumetric, acoustic and FTIR studies of intermolecular interactions in <i>n</i> -propyl acetate + diethylene glycol or triethylene glycol or tetraethylene glycol binary systems at different temperatures: experimental results and theoretical modeling

Thermophysical properties and FTIR spectra of n-propyl acetate + glycol mixtures are examined to explore the molecular interactions existing therein. By using, the measurements of densities and speeds of sound of n-propyl acetate (PAc) + diethylene glycol (DEG), + triethylene glycol (TEG) and + tetraethylene glycol (TTEG) binary mixtures across the entire range of composition at temperatures, T/K= (293.15–323.15) and pressure, p = 100 kPa. Various excess properties were evaluated using the experimental data. The partial molar volume/compressibility; excess partial molar volume/compressibility of the components over entire composition range and at infinite dilution were also calculated. These parameters were interpreted in terms of molecular interactions in these systems. Also, the speeds of sound were estimated theoretically using various theories/relations and the results were equated to experimental data. Furthermore, the FT-IR spectra of pure PAc, pure TEG and near equimolar PAc + TEG mixture were examined to confirm intermolecular interactions.