Fluid Phase Equilibria, Vol.122, No.1-2, 187-206, 1996
Partially Halogenated Hydrocarbons Chfcl-CF3, CF3-CH3, CF3-Chf-Chf2, CF3-CH2-CF3, Chf2-Cf2-Ch2F, CF3-CH2-Chf2, CF3-O-Chf2 - Critical-Temperature, Refractive-Indexes, Surface-Tension and Estimates of Liquid, Vapor and Critical Densities
For seven partially halogenated hydrocarbons, designated by the refrigeration industry as the refrigerants R124, R143a, R236ea, R236fa, R245ca, R245fa, and E125, we determined the critical temperatures T-c (ITS-90), the capillary rise, and the refractive indices of the liquid and vapor phases in the temperature range from 20 degrees C to their critical points. Independently measured liquid densities at lower temperatures, when combined with our refractive indices, produce estimates of the vapor and liquid densities at higher temperatures up to the critical point. The densities combined with the capillary rise data give the surface tensions, sigma, up to the critical points. The surface tensions of the seven refrigerants in this study together with nine others measured previously can be represented by the scaled equation sigma = 2.51(1 + 0.609 omega)k(b)T(c)(N-a/V-c)(2/3)t(1.26)(1 + 0.948t(1/2) - 0.487t) where t = (T-c - T)/T-c is the reduced temperature, and k(b), N-a, V-c, and omega are the Boltzmann and Avagadro constants, the critical volume, and the acentric factor, respectively. This equation yields values for a within 5% of the measured values for all 16 candidate replacement refrigerants.
Keywords:MIXTURES