Patent ID: 8617765

Claim:
A composition comprising a chemically stabilized, fluorinated ionomer having an inorganic filler incorporated therein, wherein the inorganic filler is a metal oxide, metal hydroxide, metal phosphate, or mixture thereof, and wherein the ionomer has been fluorinated by subjecting it to a fluorinating agent until the ionomer contains less than 200 unstable groups per 1,000,000 carbon atoms, wherein fluoride ion release in a third cycle of a Fenton Test using an acid form of the composition is in the range of 0.4 to 0.5 mgF/g of a membrane incorporating the composition, wherein in each cycle of a Fenton Test 0.6 g of dried composition is soaked in a glass tube containing 0.0029 g of FeSO 4 .7H 2 O dissolved in 50 ml of 30% hydrogen peroxide and heated at 85Â° C. for 18 hours.