Reduction of poly(tetrafluoroethylene) by aromatic radical anions: An ESR and NMR study

✍ Scribed by Hiroshi Sakurai; Yoshihiro Kubo; Masaru Shiotani; Hidenori Yahiro; Yasuhiro Okuda

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 114 KB
• Volume: 74
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19991010)74:2<286::aid-app8>3.0.co;2-s

✦ Synopsis

An ESR and 19 F-NMR study was carried out to elucidate the reduction kinetics of PTFE with aromatic radical anions (anthracene, benzophenone, biphenyl, and naphthalene), whose counter cation is Na ϩ , in THF solvent. The ESR signal intensities of aromatic radical anions decayed according to the second-order equation whose rate depends on the kind of radical anions; the relative order being naphthalene (1.00) ӷ biphenyl (0.03) Ͼ anthracene (0.02) Ͼ benzophenone (0.003). The defluorination from PTFE was examined by a high-resolution 19 F-NMR method of NaF disolved in an ethanol/water mixed solvent. When an excess amount of Na metal was present, the yield of NaF exceeded the initial concentration of aromatics. The result suggests that the aromatic radical anions are regenerated by the reaction with excess Na metal. The amounts of NaF salts produced during the reducing process were also followed by the same order as the decaying rates of aromatic radical anions.