Entropy, Heat Capacity, and Thermal Conductivity of trans-1,1,1,4,4,4-Hexafluoro-2-butene [R1336mzz(E)] Derived from the Gaseous Sound Speed Measurement

Abstract

Thermophysical properties such as entropy, heat capacity, and thermal conductivity of trans-1,1,1,4,4,4-hexafluoro-2-butene, which is designated as R1336mzz(E) for refrigerant use, were derived from the sound speed measurement in the gaseous phase. The gaseous sound speed was measured by using an acoustic-microwave resonator with a cylindrical cavity, which enables simultaneous measurement of the gaseous relative dielectric permittivity. The ideal gas heat capacity was determined from the gaseous sound speed by analyzing the measurement data with the acoustic-virial equation, and the electric dipole moment was additionally determined from the gaseous relative permittivity measurements. In compliance with the fluid-property correlation models that involve parameters associated with the ideal gas heat capacity and the dipole moment under the corresponding states principle, entropies at saturated vapor and liquid, isobaric heat capacities at saturated liquid, and thermal conductivities at vapor and liquid phases were evaluated for R1336mzz(E).