Experimental study of the density and viscosity of polyethylene glycols and their mixtures at temperatures from 293 K to 465 K and at high pressures up to 245 MPa

Density and viscosity of monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG) and their binary, (50%MEG + 50%DEG), (50%MEG + 50%TEG), (50%DEG + 50%TEG), and ternary (33.33%MEG + 33.33%DEG + 33.34%TEG) mixtures have been simultaneously measured over the temperature range from 293 K to 465 K and at pressures up to 245 MPa using the hydrostatic weighing and falling-body techniques. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15–0.30%, 0.05%, 0.02 K, and 1.5–2.0% (depending on temperature and pressure ranges), respectively. Tait-type equation of state (EOS) for pure MEG, DEG, and TEG has been developed using the measured (p, ρ, T) data. Theoretically based Arrhenius–Andrade and Vogel–Tamman–Fulcher type equation with pressure dependent coefficients was used to describe the temperature dependence of measured viscosities for pure polyethylene glycols.