| 摘要 |
Semicrystalline sulphonic fluorinated ionomers having an equivalent weight higher than 700 g/eq, up to 1,700, com- prising: (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) copoly- mer: - hydration, expressed in % of H2O at 100.degree.C absorbed by the film prepared from the ionomer and after tranforma- tion from the -SO2F form into the -SO3H form, having the following values: 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% |
