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A Helmholtz Energy Equation of State for trans-1,1,1,4,4,4-Hexafluoro-2-butene [R-1336mzz(E)]



Ryo Akasaka, Marcia L. Huber, Luke Simoni, Eric W. Lemmon


This work presents a fundamental equation of state for the thermodynamic properties of R-1336mzz(E). The equation of state is expressed explicitly in the Helmholtz energy with temperature and density as the independent variables, and is based on consistent experimental datasets, including the critical parameters, vapor pressure, saturated liquid and vapor densities, (p, ρ, T) behavior, vapor-phase sound speed, and ideal-gas isobaric heat capacity. The equation of state is valid for temperatures from 287 K to 410 K and pressures up to 5.7 MPa. In this range, expected relative uncertainties at the 95 % confidence interval (k = 2) are 0.1 % for vapor pressures, 1 % for saturated liquid densities, 1 % for saturated vapor densities, 0.15 % for liquid densities, 0.5 % for vapor densities, and 0.05 % for vapor-phase sound speeds, except in the critical region where larger uncertainties of up to 2 % are sometimes observed in densities. The equation exhibits reasonable behavior in the critical and extrapolated regions; this is demonstrated by several plots of derived properties over wide ranges of temperature and pressure. Through the use of the new equation of state, this work also formulates an extended corresponding states (ECS) model for the viscosity and thermal conductivity of R-1336mzz(E) to represent recent experimental data for these properties mostly within their experimental uncertainties.
International Journal of Thermophysics


Density · Equation of state · R-1336mzz(E) · Sound speed · Thermal conductivity · Vapor pressure · Viscosity


Akasaka, R. , Huber, M. , Simoni, L. and Lemmon, E. (2023), A Helmholtz Energy Equation of State for trans-1,1,1,4,4,4-Hexafluoro-2-butene [R-1336mzz(E)], International Journal of Thermophysics, [online],, (Accessed June 22, 2024)


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Created February 8, 2023, Updated February 16, 2023