Abstract: Graft polymeric membranes and methods for making graft polymeric membranes have one or more trifluorovinyl aromatic monomers that are radiation graft polymerized to a polymeric base film. The membranes comprise a polymeric base film to which has been graft polymerized substituted &agr;,&agr;,&bgr;-trifluorostyrene and/or &agr;,&agr;,&bgr;-trifluorovinylnaphthylene monomers, which are activated towards graft polymerization. As ion-exchange membranes, the membranes are suitable for use in electrode apparatus, including membrane electrode assemblies in, for example, fuel cells. The membranes can also be crosslinked.

Abstract: A membrane electrode assembly comprises first and second electrodes and a composite membrane interposed therebetween. The composite membrane comprises a porous substrate impregnated with a polymeric composition comprising polymerized &agr;,&bgr;,&bgr;-trifluorostyrene monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant membrane electrode assembly is useful in electrochemical applications, particularly as a membrane electrode assembly in electrochemical fuel cells.

Abstract: Graft polymeric membranes and methods for making graft polymeric membranes have one or more trifluorovinyl aromatic monomers that are radiation graft polymerized to a polymeric base film. The membranes comprise a polymeric base film to which has been graft polymerized substituted &agr;,&agr;,&bgr;-trifluorostyrene and/or &agr;,&agr;,&bgr;-trifluorovinylnaphthylene monomers, which are activated towards graft polymerization. As ion-exchange membranes, the membranes are suitable for use in electrode apparatus, including membrane electrode assemblies in, for example, fuel cells. The membranes can also be crosslinked.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of &agr;,&bgr;,&bgr;-trifluorostyrene, substituted &agr;,&bgr;,&bgr;-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.

Abstract: Graft polymeric membranes in which one or more trifluorovinyl aromatic monomers are radiation graft polymerized to a preformed polymeric base film are provided, as well as ion-exchange membranes prepared therefrom. Preferred monomers include substituted &agr;, &bgr;, &bgr;-trifluorostyrenes and trifluorovinyl naphthalenes which are activated towards the grafting reaction or facilitate the introduction of more than one ion-exchange group per monomer unit in the grafted chains. The ion-exchange membranes are useful in dialysis applications, and particularly in electrochemical applications, for example as membrane electrolytes in electrochemical fuel cells and electrolyzers.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of &agr;,&bgr;,&bgr;-trifluorostyrene, substituted &agr;,&bgr;,&bgr;-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of &agr;, &bgr;, &bgr;-trifluorostyrene, substituted &agr;, &bgr;, &bgr;-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of .alpha.,.beta.,.beta.-trifluorostyrene, substituted .alpha.,.beta.,.beta.-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.

Abstract: A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of .alpha.,.beta.,.beta.-trifluorostyrene, substituted .alpha.,.beta.,.beta.-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.

Abstract: Polymeric compositions are derived from copolymers of .alpha.,.beta.,.beta.-trifluorostyrene with a variety of substituted .alpha.,.beta.,.beta.-trifluorostyrenes. These compositions are suitable for use as membranes, particularly as ion-exchange membranes, and most particularly as solid polymer electrolytes in electrochemical applications, such as, for example, electrochemical fuel cells.

Abstract: Sulfonyl fluoride substituted .alpha.,.beta.,.beta.-trifluorostyrene monomers are disclosed. The monomers are incorporated into polymeric compositions which are conveniently hydrolyzed to produce polymeric compositions which include ion-exchange moieties. The resulting compositions which include ion-exchange moieties are particularly suitable for use as solid polymer electrolytes in electrochemical applications, such as, for example, electrochemical fuel cells.

Abstract: Sulfonyl fluoride substituted .alpha.,.beta.,.beta.-trifluorostyrene monomers are disclosed. The monomers are incorporated into polymeric compositions which are conveniently hydrolyzed to produce polymeric compositions which include ion-exchange moieties. The resulting compositions which include ion-exchange moieties are particularly suitable for use as solid polymer electrolytes in electrochemical applications, such as, for example, electrochemical fuel cells.

Abstract: Polymeric compositions are derived from copolymers of .alpha.,.beta., .beta.-trifluorostyrene with a variety of substituted .alpha.,.beta.,.beta.-trifluorostyrenes. These compositions are suitable for use as membranes, particularly as ion-exchange membranes, and most particularly as solid polymer electrolytes in electrochemical applications, such as, for example, electrochemical fuel cells.

Abstract: A gasketed membrane electrode assembly for electrochemical fuel cells employs gasketing material at the periphery of the ion exchange membrane, rather than the membrane itself, as a gasket. The gasketing material may be formed from an elastomeric material suitable for cold bonding or bonding by heat and pressure. A nonhydrophilic thermoplastic elastomer is the preferred gasketing material. The gasketed membrane electrode assembly provides a seal between the electrically conductive separator plates that is more effective and economical than assemblies employing the membrane itself as the gasketing material. In an alternative embodiment, a gasketed membrane assembly for use in the humidification portion of a fuel cell employs gasketing material at the periphery of a water permeable membrane.

Abstract: Polymeric compositions are derived from copolymers of .alpha.,.beta.,.beta.-trifluorostyrene with a variety of substituted .alpha.,.beta.,.beta.-trifluorostyrenes. These compositions are suitable for use as membranes, particularly as ion-exchange membranes, and most particularly as solid polymer electrolytes in electrochemical applications, such as, for example, electrochemical fuel cells.