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 tetramethylethyl enediamine(a) (TMEDA) as a catalyst. As evidenced by infrared (IR) spe ctroscopy, X-ray photoelectron spectroscopy (XPS) and elemental analys is the C4H9-, C8H17-, C12H25- or phenyl groups were attached to a part ly defluorinated macromolecular chain. Analogous reactions with dilith ioaryl 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 >15 0 degrees C, the defluorination is almost quantitative even in the abs ence of the catalyst. The TMEDA-catalyzed reaction proceeds via elimin ation and nucleophilic addition. On the other hand, more concentrated RLi in the absence of the catalyst seems to react via a radical mechan ism.