Transport properties of Freon-152a and Freon-142b in the temperature range of 280–510 K

The thermal conductivity of 1,1 difluoroethane (Freon-152a) and 1 chloro-1 difluoroethane (Freon-142b) are measured at several pressures in the range 29.7–75.8 kPa and as a function of temperature in the range 280–510 K. The thermal conductivity column instrument is employed, and the experimental values are estimated to be accurate within a maximum uncertainty of ±5.6% at the lowest temperature, which reduces to ±2.4% at the highest temperature. These conductivity values are compared with the predictions of Chapman-Enskog kinetic theory, with the correction factor for the internal energy transport estimated from Hirschfelder's theory, and the Lennard-Jones (12-6) potential. The experimental conductivity data are also utilized to generate the values for the two other transport properties in conjunction with the interrelations obtained between different properties on the basis of kinetic theory. The data on transport properties are employed to give the best possible estimates of Prandtl and Schmidt numbers as a function of temperature.