Abstract: Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.

Abstract: An electrolyte membrane is formed by an acidic polymer and a low-volatility acid that is fluorinated, substantially free of basic groups, and is either oligomeric or non-polymeric.

Abstract: The present invention is a fluoropolymer comprising a plurality of pendent groups terminating in —CF2SO3X, —CF2SO2F, or combinations thereof, where X is selected from a group consisting of H+ and a monovalent cation, and at least one —CF2Y end group, where Y is selected from a group consisting of a chlorine atom, a bromine atom, an iodine atom, a nitrile group, and an —SO3X group.

Abstract: A method of making a crosslinked polymer is provided as well as the polymer so made, the method comprising the steps of: providing a highly fluorinated fluoropolymer, typically a perfluorinated fluoropolymer, comprising pendent groups which include a group according to the formula —SO2X, where X is F, Cl, Br, OH, or —O?M+, where M+ is a monovalent cation, and exposing said fluoropolymer to electron beam radiation so as to result in the formation of crosslinks. Typically, the method according to the present invention additionally comprises the step of: forming said fluoropolymer into a membrane, typically having a thickness of 90 microns or less, more typically 60 microns or less, and most typically 30 microns or less.

Abstract: A fuel cell membrane electrode assembly is provided comprising a polymer electrolyte membrane which comprises a polymer that comprises bound anionic functional groups, wherein the polymer electrolyte membrane additionally comprises cerium cations. In another aspect, a fuel cell membrane electrode assembly is provided comprising a polymer electrolyte membrane which comprises a polymer that comprises bound anionic functional groups, wherein at least a portion of the anionic functional groups are in acid form and at least a portion of the anionic functional groups are neutralized by cerium cations. In another aspect, a polymer electrolyte membrane is provided which comprises a polymer that comprises bound anionic functional groups, wherein the polymer electrolyte membrane additionally comprises cerium cations, and wherein the amount of cerium cations present is between 0.001 and 0.

Abstract: A fuel cell membrane electrode assembly is provided comprising a polymer electrolyte membrane which comprises a highly fluorinated polymer electrolyte and at least one cerium oxide compound dispersed therein. In addition, a method of making a fuel cell polymer electrolyte membrane is provided comprising the steps of: a) providing a highly fluorinated polymer electrolyte comprising acidic functional groups; b) dispersing therein at least one cerium oxide in an amount so as to provide between 0.01 and 5 percent of the total weight of the polymer electrolyte membrane; and c) thereafter forming a polymer electrolyte membrane comprising said polymer electrolyte.

Abstract: The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

Abstract: The present invention is a fluoropolymer comprising a plurality of pendent groups terminating in —CF2SO3X, —CF2SO2F, or combinations thereof, where X is selected from a group consisting of H+ and a monovalent cation, and at least one —CF2Y end group, where Y is selected from a group consisting of a chlorine atom, a bromine atom, an iodine atom, a nitrile group, and an —SO3X group.

Abstract: A method is provided for making a crosslinked polymer electrolyte, typically in the form of a membrane for use as a polymer electrolyte membrane in an electrolytic cell such as a fuel cell, by trimerization of nitrile groups contained on groups pendant from the polymer. The resulting polymer electrolyte membrane comprises a highly fluorinated polymer comprising: a perfluorinated backbone, first pendent groups which comprise sulfonic acid groups, and crosslinks comprising trivalent groups according to the formula: The first pendent groups are typically according to the formula: —R1—SO3H, where R1 is a branched or unbranched perfluoroalkyl or perfluoroether group comprising 1-15 carbon atoms and 0-4 oxygen atoms, most typically —O—CF2—CF2—CF2—CF2—SO3H or —O—CF2—CF(CF3)—O—CF2—CF2—SO3H.

Abstract: A method is provided for obtaining crosslinked polymers having pendent sulfonic acid groups by crosslinking through the sulfonic acid groups or their precursors with aromatic crosslinkers or aromatic pendent crosslinking groups to form aromatic sulfones. Such crosslinked polymers may be used to make polymer electrolyte membranes (PEM's) that may be used in electrolytic cells such as fuel cells.

Abstract: Methods of manufacturing a film involve providing a coating of an ion-containing polymer or ion-containing polymer precursor and annealing the coating to form a film using microwave radiation. Methods of manufacturing an ion-containing membrane for use in a membrane electrode assembly of a fuel cell involve coating a solution of an ion-containing polymer or ion-containing polymer precursor to form a cast membrane of the membrane electrode assembly, and annealing the cast membrane using microwave radiation. The cast membrane may comprise a PEM, for example, which may be incorporated in a fuel cell assembly.

Abstract: Fuel cell membrane electrode assemblies and fuel cell polymer electrolyte membranes are provided comprising bound anionic functional groups and polyvalent cations, such as Mn or Ru cations, which demonstrate increased durability. Methods of making same are also provided.

Abstract: Fuel cell membrane electrode assemblies and fuel cell polymer electrolyte membranes are provided comprising manganese oxides which demonstrate increased durability. Methods of making same are provided.

Abstract: Anionic species are removed from aqueous dispersions of ionic fluoropolymers using anion exchange resins. In some embodiments, cationic species are also removed using cation exchange resins.

Abstract: Aqueous dispersions of fluoropolymers having fluorosulfonyl groups are hydrolyzed to form dispersions of ionic fluoropolymers by addition of base.

Abstract: A method is provided for making a crosslinked polymer electrolyte, typically in the form of a membrane for use as a polymer electrolyte membrane in an electrolytic cell such as a fuel cell, as well as the polymer so made, the method comprising application of ultraviolet radiation to a highly fluorinated fluoropolymer comprising: a backbone derived in part from tetrafluoro-ethylene monomer, first pendent groups which include a group according to the formula —SO2X, where X is F, Cl, Br, OH or —O?M+, where M+ is a monovalent cation, and second pendent groups which include Br, Cl or I. Typically, the membrane has a thickness of 90 microns or less, more typically 60 or less, and most typically 30 microns or less.

Abstract: A method is provided for obtaining crosslinked polymers, particularly fluorinated polymers having pendent sulfonic acid groups, by crosslinking through pendent groups which include a sulfonyl chloride group (—SO2Cl). The sulfonyl chloride group may be removed by application of electromagnetic radiation, typically in the ultraviolet band, or a radical initiator, leaving behind a radical which readily binds covalently to other polymer strands or to crosslinking agents to form crosslinks. Typically, the polymer is made by providing a polymer comprising pendent groups which include a group according to the formula —SO2F and converting at least a portion of the —SO2F groups to —SO2Cl. After crosslinking, the remaining —SO2F groups may be converted to sulfonic acid groups, yielding a crosslinked polymer electrolyte. Such crosslinked polymer electrolytes may be used to make polymer electrolyte membranes (PEM's) that may be used in electrolytic cells such as fuel cells.

Abstract: Methods are provided to make acid functional fluoropolymers by: a) dehydrofluorinating a starting fluoropolymer with a dehydrofluorinating agent to form an unsaturated fluoropolymer; b) adding an acidifiable nucleophilic functionalizing agent to a double bond of the unsaturated fluoropolymer; and c) acidifying the added acidifiable function. Acid functional fluoropolymers and ion conducting membranes thereof are also provided, including acid functional fluoropolymer having pendent groups according to the formula: —X—Ar-An, wherein X is selected from O, S or NR, where R is selected from H and C1-C30 alkyl or aryl, which are optionally substituted, wherein Ar is a C6-C30 aromatic group, which is optionally substituted, wherein A is an acidic function or salt thereof, wherein a can be independently chosen to be 1, 2 or 3.

Abstract: A method is provided for obtaining crosslinked polymers having pendent sulfonic acid groups by crosslinking through the sulfonic acid groups or their precursors with aromatic crosslinkers or aromatic pendent crosslinking groups to form aromatic sulfones. Such crosslinked polymers may be used to make polymer electrolyte membranes (PEM's) that may be used in electrolytic cells such as fuel cells.

Abstract: A method of making a crosslinked polymer is provided as well as the polymer so made, the method comprising the steps of: providing a highly fluorinated fluoropolymer, typically a perfluorinated fluoropolymer, comprising pendent groups which include a group according to the formula —SO2X, where X is F, Cl, Br, OH, or —O?M+, where M+ is a monovalent cation, and exposing said fluoropolymer to electron beam radiation so as to result in the formation of crosslinks. Typically, the method according to the present invention additionally comprises the step of: forming said fluoropolymer into a membrane, typically having a thickness of 90 microns or less, more typically 60 microns or less, and most typically 30 microns or less.