What are fluorocarbons? Give their method of preparation, properties and commercial applications
- Fluorocarbons, sometimes referred to as perfluorocarbons or PFCs, i.e. they contain only C and F, though the terminology is not strictly followed.
- Compounds with the prefix perfluoro- are hydrocarbons, including those with heteroatoms, wherein all C-H bonds have been replaced by C-F bonds. Fluorocarbons can be perfluoroalkanes, fluoroalkenes and fluoroalkynes and perfluoroaromatic compounds.
- A major breakthrough that allowed the large scale manufacture of fluorocarbons was the Fowler Process.
- C
6
- H
14
- + 28 CoF
3
- → C
6
- F
14
- + 14 HF + 28 CoF
2
- The resulting cobalt difluoride is then regenerated, sometimes in a separate reactor:
- 2 CoF
2
- + F
2
- → 2 CoF
3
- Industrially, both steps are combined, for example in the manufacture of the Flutec range of fluorocarbons by F2 chemicals Ltd, using a vertical stirred bed reactor, with hydrocarbon introduced at the bottom, and fluorine introduced halfway up the reactor. The fluorocarbon vapor is recovered from the top.