A liquid composition comprising at least one aprotic organic solvent and at least one fluorinated ion exchange polymer which consists of recurring units derived from a chlorofluoroolefin of formula CF.sub.2CCIY, wherein Y is F or CI, and from at least one fluorinated functional monomer selected among those of formula CF.sub.2CFO(CF.sub.2CF(CF.sub.3)O).sub.m(CF.sub.2).sub.nSO.sub.2X, wherein m is an integer equal to 0 or 1, n is an integer from 0 to 10 and X is chosen among halogens (CI, F, Br, I), O.sup.M.sup.+, wherein M.sup.+ is a cation selected among H.sup.+, NH.sub.4.sup.+, K.sup.+, Li.sup.+, Na.sup.+, or mixtures thereof is disclosed. The liquid composition is suitable for the preparation of ion exchange membranes, in particular composite membranes, for use in fuel cell applications.

A liquid composition comprising at least one aprotic organic solvent and at least one fluorinated ion exchange polymer which consists of recurring units derived from a chlorofluoroolefin of formula CF.sub.2CCIY, wherein Y is F or CI, and from at least one fluorinated functional monomer selected among those of formula CF.sub.2CFO(CF.sub.2CF(CF.sub.3)O).sub.m(CF.sub.2).sub.nSO.sub.2X, wherein m is an integer equal to 0 or 1, n is an integer from 0 to 10 and X is chosen among halogens (CI, F, Br, I), O.sup.M.sup.+, wherein M.sup.+ is a cation selected among H.sup.+, NH.sub.4.sup.+, K.sup.+, Li.sup.+, Na.sup.+, or mixtures thereof is disclosed. The liquid composition is suitable for the preparation of ion exchange membranes, in particular composite membranes, for use in fuel cell applications.

A method of exchanging or transforming end groups in and/or improving the ferroelectric properties of a PVDF-TrFE co-polymer is disclosed. A bulky or chemically dissimilar end group, such as an iodine, sulfate, aldehyde or carboxylic acid end group, may be transformed to a hydrogen, fluorine or chlorine atom. A method of making a PVDF-TrFE co-polymer is disclosed, including polymerizing a mixture of VDF and TrFE using an initiator, and transforming a bulky or chemically dissimilar end group to a hydrogen, fluorine or chlorine atom. A PVDF-TrFE co-polymer or other fluorinated alkene polymer is also disclosed. The co-polymer may be used as a ferroelectric, electromechanical, piezoelectric or dielectric material in an electronic device.

Tapes, expanded tapes, and methods of making the same. The tapes and expanded tapes include long-strand PTFE fibrils, short-strand PTFE fibrils, and an oriented network. The oriented network includes nodes. The nodes include active particles and short-strand PTFE fibrils distributed among the active particles.

Tapes, expanded tapes, and methods of making the same. The tapes and expanded tapes include long-strand PTFE fibrils, short-strand PTFE fibrils, and an oriented network. The oriented network includes nodes. The nodes include active particles and short-strand PTFE fibrils distributed among the active particles.

A method of producing a fluorine-containing compound is a method of producing a compound (30) having partial structure (3) by an insertion reaction of compound (20) into compound (10) that has partial structure (1), in the presence of an ionic catalyst formed from a specific monovalent anion and a counter cation. In the formulas, * represents a bonding site, and X.sup.1 and R.sup.1 to R.sup.4 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, or an organic group having a carbon number of 1 to 20 which may have a substituent. ##STR00001##