ML-3 3 Par-Physical Property Data on Fluorinated Propanes and Butanes as CFC and HCFC Alternatives

The authors are investigating fluorinated propane derivatives as second generation alternatives for currently used CFC and HCFC chemicals. One fluorinated ether was also studied. These investigations have included both (i) synthesis and (ii) the measurement and estimation of their physical properties. In this paper we will describe only the results of the physical property investigations. A total of 22 compounds were investigated with boiling points ranging from -34.6OC to 76.7OC. The measured properties presented for these compounds include: melting point, boiling point, vapor pressure below the boiling point, heat of vaporization, critical properties (temperature, density and pressure), liquid densities, and liquid phase heat capacities. Measured vapor pressures are reported from below the boiling point up to the critical point for two of these compounds; E-125a (b.p.=-34.6OC and Tc= 80.7OC), and HFC236ea (b.p.=6.50C and Tcel 4 1.1 OC). For the readers convenience the chemical formula that corresponds to the ASHRAE number code is provided in Table 1A of the Appendix to this paper. Vapor pressure5 and liquid phase densities were aka measured for CFC-12 in order to judge the accuracy of our experimental methods. The measured vapor pressures were also compared with vapor pressures estimated using modified corresponding states methods’ to evaluate the accuracy of these estimation methods.