Reactivity of polymeric carbon chains reduced from poly(tetrafluoroethylene)

Electrochemical reduction of poly(tetrafluoroethylene) (Teflon), which contains very long linear carbon atom chains, yields in the presence of Li⁺ a solid mixture of lithium fluoride and polymeric carbon. The latter is probably in the sp state and is very chemically reactive. Its chains begin to bind into a solid carbon skeleton only after separation from the salt sheaths, so that chemical bonds are formed between certain carbon atoms of neighbouring chains. The form of the skeleton is much influenced by physico-chemical conditions during the separation process. The porous carbon layer consisting from sporadically bound carbon chains was found to be plastic as long as the skeleton does not become more rigid by the formation of additional chemical bonds. Three different carbonaceous materials were prepared from the same mixture (C, LiF) by different technologies. Differences between them were studied by elementary chemical analysis, nitrogen adsorption, wide-angle and small-angle X-ray scattering, and electron microscopy. The obtained results enable to discuss the course of formation of the carbon skeleton.