Measurement of thermal conductivity of liquid fluorocarbons

The thermal conductivity of ten liquid fluorocarbons, R 11, R 12, R 13, R 13B1, R 22, R 113, R 114, R 115, R 114B2, and R 124, was measured in the temperature range from 204–450 K by using the transient hot wire method. Prior to the measurement of the fluorocarbons, the thermal conductivity of toluene as the reference material was measured. The results for toluene agree with the recommended values by Nagasaka and Nagashima within ±1%. The accuracy of the present results for fluorocarbons is estimated to be better than ±1.5%. The results are compared with the equation by Li and Poole. The equation proves to be unsuitable for some fluorocarbons, and modified Li-Poole equations including the number of fluorine atoms are proposed for the three groups of fluorocarbons based on the smoothed values of this work and are compared with the experimental data.