Study on the synthesis of perfluorovinyl-sulfonic functional monomer and its copolymerization with tetrafluoroethylene

✍ Scribed by G. K. Kostov; St. V. Kotov; G. D. Ivanov; D. Todorova

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 511 KB
• Volume: 47
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1993.070470417

✦ Synopsis

Tetrafluoroethylene ( TFE ) and hexafluoropropylene ( HFP ) were subjected to reactions with freshly distilled sulfur trioxide to obtain 1-fluorosulfonyldifluoro-acetylfluoride (FSDFAF, yield 65-70% ) and pentafluoro-2-propenylfluorosulfate (PPFS, yield up to 50% ) .

A subsequent reaction of FSDFAF with PPFS under anhydrous conditions led to a preparation of 2-( 1-pentafluoro-2-propenyloxy ) tetrafluoroethanesulfonyl fluoride ( PPOTESF, yield 40-41% ) whose structure was proved by both infrared (IR) spectroscopy and nuclear magnetic resonance ("F NMR) . TFE was copolymerized with PPOTESF in bulk by using a free radical initiator of the hydrocarbon type at a temperature of 50°C. Various TFE/ PPOTESF mole ratios were employed and the presence of sulfonyl fluoride (-SOZF) functional groups in the copolymers was proven by IR spectroscopy. The copolymers were subjected to alkaline hydrolysis and the -SOzF content was found not to exceed 0.70-0.80 mEq/g with polymer yields in the range of 11-31%. The reactivity ratios rl and rz related to TFE and PPOTESF, respectively, were determined by using the Fineman-Ross method. A random distribution of PPOTESF units along the polymeric chain, consisting mainly of TFE fragments, was found to exist. The copolymers had melting temperatures 40-45OC lower than polytetrafluoroethylene and were thermally stable to 305-315°C.