Density, Viscosity, Spectra and Quantum Chemistry Analysis of Dimethyl Sulfoxide and Ethylene Glycol Propyl Ether Mixtures

The density (ρ) and dynamic viscosity (η) values of the binary mixed solution (ethylene glycol propyl ether (2-PE) and dimethyl sulfoxide (DMSO)) with different concentrations were measured by Ubbelohde viscometer (0.8–0.9 mm in diameter) and 25 mL pycnometer at atmospheric pressure and 293.15–318.15 K of the temperature. According to the ρ and η values, the viscosity deviation ( \(\Delta {{\eta }}\) ), excess molar volume ( \(V_{m}^{E}\) ), partial molar volume ( \({{\bar {V}}_{{\text{1}}}}\) , \(~{{\bar {V}}_{{\text{2}}}}\) ), apparent molar volume ( \({{V}_{{\not\bigcirc {\text{,1}}}}}\) , \(~{{V}_{{\not\bigcirc {\text{,2}}}}}\) ), excess Gibbs energy of activation for viscous flow ( \(\Delta {{G}^{E}}\) ), and thermal expansion coefficient ( \({{{{\alpha }}}_{p}}\) ) of the mixed solution were obtained by the calculation method. In addition, the intermolecular forces between 2-PE and DMSO were analyzed by infrared spectra (FTIR), ultraviolet spectra (UV–Vis) and fluorescence spectra. The results showed that hydrogen bond is formed between the hydrogen atom on hydroxyl of 2-PE and oxygen atom of DMSO, and the hydrogen bond affects the physical properties of the binary system. Based on the analysis above, the result was interpreted as (CH₃)₂S=O···HOCH₂CH₂OCH₂CH₂CH₃.