Absolute Viscosity of CCl 2 F 2 and CHCl 2 F

Abstract

The absolute viscosity at atmospheric pressure was determined experimentally for the vapour phase of two halogenated hydrocarbon compounds, refrigerants R12 (CCl₂F₂) and R22 (CHCl₂F) in the general temperature range −39·7° to 91·8°C.

The maximum error of the data is believed to be ±3 per cent. Comparison with previous secondary measurements on the same compounds reveals that the maximum deviation of previous measurements are +5 per cent and −6 per cent for R12 and R22, respectively, over the common temperature range.

The data obtained in this work and by others were correlated using third and fourth degree polynomials, a power function of the absolute temperature, and a collision theory approach, which yielded values for the reduced dipole energy, the velocity collision diameter, and the maximum energy of attraction for the molecules. Comparison of the data with that predicted by simple kinetic theory has been made.