To provide a polymer wherein a linking group that connects the main chain of the polymer and a cyclic perfluoroaliphatic disulfonimide skeleton, is a fluoroalkylene group which may have an ether oxygen atom. A polymer which has either one or both of units represented by formula u1-1 and units represented by formula u1-2: ##STR00001##
R.sup.F1, R.sup.F2: a C.sub.1-3 perfluoroalkylene group; R.sup.F3: a C.sub.1-6 perfluoroalkylene group; m: 0 or 1; and X: a hydrogen atom, an alkali metal atom, a fluorine atom, an alkyl group, ammonium or the like.

To provide a polymer wherein a linking group that connects the main chain of the polymer and a cyclic perfluoroaliphatic disulfonimide skeleton, is a fluoroalkylene group which may have an ether oxygen atom. A polymer which has either one or both of units represented by formula u1-1 and units represented by formula u1-2: ##STR00001##
R.sup.F1, R.sup.F2: a C.sub.1-3 perfluoroalkylene group; R.sup.F3: a C.sub.1-6 perfluoroalkylene group; m: 0 or 1; and X: a hydrogen atom, an alkali metal atom, a fluorine atom, an alkyl group, ammonium or the like.

The present invention pertains a fluoropolymer [polymer (F)] comprising: recurring units derived from at least one ethylenically unsaturated fluorinated monomer [monomer (FM)]; from 5% to 60% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived at least one ethylenically unsaturated fluorinated monomer containing at least one SO.sub.2F functional group [monomer (IO)]; and from 0.01% to 10% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived from at least one monomer comprising an azide group [monomer (Az)], to a process for its manufacture, to a cross-linkable composition comprising the same, to a process for cross-linking the same and to articles comprising the cross-linked polymer.

The present invention pertains a fluoropolymer [polymer (F)] comprising: recurring units derived from at least one ethylenically unsaturated fluorinated monomer [monomer (FM)]; from 5% to 60% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived at least one ethylenically unsaturated fluorinated monomer containing at least one SO.sub.2F functional group [monomer (IO)]; and from 0.01% to 10% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived from at least one monomer comprising an azide group [monomer (Az)], to a process for its manufacture, to a cross-linkable composition comprising the same, to a process for cross-linking the same and to articles comprising the cross-linked polymer.

According to one embodiment, a composition including a compound is provided. The compound includes a linking group containing 2 to 18 carbon atoms, a polymerizable functional group bonded to the linking group, a first reactive group bonded to the linking group, and a second reactive group bonded to the linking group. The polymerizable functional group includes at least one of a (meth)acryloyl group or a vinyl group. The first reactive group includes at least one selected from the group consisting of a thiol group, a disulfide group, and a thiocyanate group. The second reactive group includes at least one selected from the group consisting of an alkoxysilane group, a chlorosilane group, and a hydroxyl group.