Thermodynamic, transport and optical properties of formamide + 1,2-ethanediol, 1,3-propanediol and poly (ethylene glycol) 200 binary liquid mixtures

Densities and viscosities of formamide (FA) + 1,2-ethanediol (1,2-ED), 1,3-propanediol (1,3-PD) and poly (ethylene glycol) 200 (PEG 200) binary liquid mixtures at temperatures of 293.15, 298.15 and 303.15 K and refractive indices at T = 298.15 K were measured over the entire range of composition and atmospheric pressure (0.1 MPa). From the experimental measurements, several thermophysical properties including the excess molar volumes (VmE), coefficient of thermal expansion αP, excess coefficient of thermal expansion αPE, partial molar volume V − mi , excess refractive index nE and excess viscosity ηE were calculated. The obtained excess parameters were used to discuss the inter-intra molecular interactions in the liquid mixtures. Moreover, the excess properties were correlated with Redlich-Kister polynomial equation and the viscosities were correlated with Eyring–Margules, McAllister and Andrade models. Finally, Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equation of state were applied to the densities of studied binary mixtures to examine the ability of these models to predict thermodynamic properties.