THE HEAT-CAPACITY OF FLUORINATED PROPANE AND BUTANE DERIVATIVES BY DIFFERENTIAL SCANNING CALORIMETRY

The constant pressure liquid-phase heat capacities of 21 hydrogen containing fluorinated propane and butane derivatives and one fluorinated ether (CF3OCF2H) with boiling points ranging from-34.6-degrees to 76.7-degrees-C have been measured to 3% accuracy by differential scanning calorimetry at 40-degrees-C. The measurements are needed to help identify alternative refrigerants and blowing agents that do not deplete the stratospheric ozone layer. The DSC method has two significant advantages for this purpose, which are: (i) only small samples (less than 100 mg) are required, and (ii) the instruments are available in many laboratories and can be used for the heat capacity measurement of liquids with subambient boiling points without modification or special accessories.