Polymerization products formed from a monomeric mixture comprising (a) one or more first monomers of the general formula I: A-L-R.sup.1--(X--CF.dbd.CF.sub.2).sub.n (I) wherein R.sup.1 represents one or more inertly substituted groups; X is independently a group which links the inertly substituted groups and the trifluorovinyl group; L is an optional linking group; A is CO.sub.2Z, SO.sub.2Z, PO.sub.3Z, or OPO.sub.3Z wherein Z is hydrogen or an alkali metal and n is an integer of 1 to about 1000; (b) one or more second crosslinking monomers comprising at least three trifluorovinyl groups and (c) one or more prepolymers comprising one or more trifluorovinyl groups are provided. Also provided are biomedical devices formed from such polymerization products.