Fluorinated ionomers

Abstract

Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, comprising: (A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation; (B) fluorinated monomeric units containing sulphonyl groups —SO2F in such amount to give the above equivalent weight, deriving from F2C═CF—O—(CF2)q—SO2F, q being an integer equal to 2 or 3; and having the following properties for a TFE/(B) copolymer: hydration, expressed in % of H2O at 100° C. absorbed by the film prepared from the ionomer and after tranformation from the —SO2F form into the —SO3H form, having the following values: 1 at 750 EW higher than 55%, pref. >70% at 850 EW ″ 45%, ″ >55% at 1,000 EW ″ 35%, ″ >40% at 1,100 EW ″ 28%, ″ >32% at 1,200 EW ″ 23%, ″ >25%

Dependencies are inferred from the claim text.