Critical Properties of Fluorinated Ethers

Using a static-type apparatus, we measured the critical temperatures, pressures, and densities of seven fluorinated ethers: CF3CHFOCHF2, CF3CF2OCH3, CF3CH2OCH3, CF3CF2OCH2CF3, CF3CF2OCH2CH3, CF3,CF2CF2OCH3, and (CF3)2CFOCH3. The advantage of the measuring apparatus was that a small amount of a sample was sufficient to determine the critical properties accurately. The uncertainties of the critical properties measured in this work were ±30 mK in temperature, ±2 kPa in pressure, and ±0.2% in density, respectively. The critical properties of the compounds were compared with those estimated by the Lydersen group contribution method.