Synthesis and polymerization of fluorinated monomers bearing a reactive lateral group?part 8?study of the tetrafluoroethylene-propylene rubber modification by 4,5,5-trifluoro-4-penten-1-ol as a comonomer

Abstract

The radical terpolymerization of tetrafluoroethylene (TFE) with propylene (P) and 4,5,5-trifluoro-4-penten-1-ol (FA3) for the synthesis of fluorinated polymers bearing hydroxy side groups is presented. The polymerization was carried out in emulsion and in a batch operation, initiated by a redox system containing tert-butylperoxybenzoate. The reaction proceeded without any induction period and in a stationary state at low conversion (up to 12%). The presence of the trifluorovinyl hydroxy monomer in the ternary system sharply decreased the polymerization rate, in contrast to that of the TFE/P binary one. The order of the reaction about FA3 was 1.25. The terpolymer compositions were determined by elemental analysis by 1H- and 19F-NMR spectroscopy. An almost equimolar ratio of TFE and P base units in the terpolymer was found, while the FA3 was inserted between TFE/P blocks. The presence of P increased the polymerization rate and lowered the chain transfer coming from FA3 when compared to the TFE/FA3 binary system. Thermal properties were assessed. The glass transition temperatures (Tg) slightly decreased with the FA3 content. The decomposition temperatures were also affected, showing two steps of decomposition related to the amount of FA3 in the copolymer, and is discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3991–3999, 1999