Nonideality of Ethylene Glycol and Propylene Carbonate Mixtures Based on the Density, Refractive Index, and Viscosity: Experiment and Modeling

The nonideality of a liquid mixture is determined by the molecular interactions that occur within a solution. These interactions between molecules affect various solution properties, such as the density, refractive index, and viscosity. Understanding the deviation from ideality is essential for interpreting how molecules interact in a solution. The assessment of this information is fundamental to the testing and development of molecular theories and mathematical models. This study presents an analysis of the density, refractive index, kinematic viscosity, and dynamic viscosity of a binary liquid mixture of ethylene glycol and propylene carbonate. The study covers the entire solution mole fraction at different temperatures. The experimental data of density was analyzed using the Peng–Robinson and PC-SAFT equations of state. The values of kinematic viscosity were applied to the Eyring equation associated with the NRTL activity coefficient model, and the data for the refractive index were tested by the Lorentz–Lorenz N-mixing rule. The nonideality of the mixture was attributed to the formation and breaking of hydrogen bonds between molecules of ethylene glycol. The models used in this study demonstrate their capability to treat the experimental data.