Viscosity measurements and correlations of binary mixtures: 1,1,1,2-tetrafluoroethane (HFC-134a) + tetraethylene glycol dimethylether (TEGDME)

This paper reports viscosity data for the binary system1,1,1,2-tetrafluoroethane (HFC-134a), x1, +tetraethylene glycol dimethylether (TEGDME), 1 − x1. The measurements (200 data points) were obtained at various pressures (between 10 and 100 MPa) in the homogeneous liquid state from T = 293.15–373.15 K. The measurements have been carried out with a falling body viscometer for four molar fractions x1 = (0.28, 0.44, 0.63 and 0.88). The density values of this system were interpolated from previous results obtained at the laboratory. All of the available viscosity data, including pure HFC-134a and pure TEGDME (both previously studied at the laboratory), have been correlated using several viscosity models (mixing rules, self-refrencing model, hard-sphere theory, friction theory and free volume model). The resulting models are presented and discussed in this work.