Abstract |
The paper discusses the possibility of fluorinated ethers' being a new family of halons. Work at the University of Tennessee to find suitable replacements for fully halogenated chlorofluorocarbons (CFCs) and halons has centered on the incorporation of oxygen as a heteroatom. The most stable class of compounds, fluorinated ethers, potentially doubles the number of candidates versus just the halogenated alkanes, with minimal change in physical properties. The first comparison of compounds involves the dimethyl ether series of compounds which provide substitutionally similar analogs to ethanes. The synthesis, characterization, and physical properties of all of the perfluorinated ethers are discussed briefly and their extinguishment concentrations are tabulated. The work indicates that the mechanism by which perfluorocarbons achieve their flame extinguishment capability is rooted more in the ability to dissipate the energy of free radicals and permit their recombindation, than it is by any bond dissociative or other purely chemical mechanism. This implies that, in the absence of overriding chemical effects (bromine), there should be a correlation between infrared absorptivity and extinguishant effectiveness. |