Simultaneous fluorine elimination and alkylation of poly(tetrafluoroethylene)

PTFE (powder or foils) was defluorinated and derivatized in a one‐step process by alkyl‐ and aryllithium in the presence of tetramethylethylenediamine Systematic name: 1,2‐Bis‐[dimethylamino]ethane. (TMEDA) as a catalyst. As evidenced by infrared (IR) spectroscopy, X‐ray photoelectron spectroscopy (XPS) and elemental analysis the C 4 H 9 ‐, C 8 H 17 ‐, C 12 H 25 ‐ or phenyl groups were attached to a partly defluorinated macromolecular chain. Analogous reactions with dilithioaryl or dilithioalkyl agents presumably lead to crosslinking of the polymeric chains through alkyl or aryl groups. When the PTFE powder is treated with more concentrated RLi (>3 mol L −1 ) at temperatures >150°C, the defluorination is almost quantitative even in the absence of the catalyst. The TMEDA‐catalyzed reaction proceeds via elimination and nucleophilic addition. On the other hand, more concentrated RLi in the absence of the catalyst seems to react via a radical mechanism.