Unveiling the intermolecular interactions in ethyl acetate + polyethylene glycol 200/300/400/600 binary mixtures by using densities, speeds of sound, excess properties and FTIR spectra at different temperatures

The intermolecular interactions in ethyl acetate + polyethylene glycols (PEG) mixtures were examined by means of the excess and partial molar properties and FTIR spectra. The measurements of density and speed of sound of ethyl acetate + polyethylene glycols (PEG 200, PEG 300, PEG 400 and PEG 600) binary mixtures have been carried out over whole composition range at temperature from 293.15  K to 323.15  K and pressure, p = 100  kPa. The ρ and u data have been used to calculate excess properties, viz., excess molar volume, excess isentropic compressibility, excess intermolecular free length, excess speed of sound and excess molar isentropic compressibility. In addition, the partial molar volume/compressibility; excess partial molar volume/compressibility of the components over the entire composition range, and at infinite dilution have also been calculated. The variations in these properties with composition and temperature have been conversed in terms of existing intermolecular interactions in these mixtures. The ethyl acetate-PEG interactions in these mixtures follow the order: PEG 600 > PEG 400 > PEG 300 > PEG 200. The speeds of sound were estimated theoretically by using the scaled particle theory and were compared with the experimental values. Furthermore, FT-IR spectra of pure ethyl acetate, PEG 200 and their equimolar mixture were also recorded and analysed to confirm the prevailing intermolecular interactions.