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Assignee3M Innovative Properties Company
InventorsGregg D. Dahlke, Denis Duchesne, Klaus Hintzer, Markus E. Hirschberg, Kai H. Lochhaas, Arne Thaler, Tilman C. Zipplies
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A method of making a copolymer is disclosed. The method includes copolymerizing components including tetrafluoroethylene and a compound represented by formula CF2═CF—O—(CF2)a—SO2X, wherein “a” is a number from 1 to 4, and X is —NZH, —NZ—SO2—(CF2)1-6—SO2X′, or —OZ, wherein Z is independently a hydrogen, an alkali metal cation, or a quaternary ammonium cation, and wherein X′ is independently —NZH or —OZ. The components include at least 60 mole % of tetrafluoroethylene based on the total amount of components. A copolymer prepared by the method is also provided. A method of making a membrane using the copolymer is also provided. The present disclosure also provides a polymer electrolyte membrane that includes a copolymer made by the method and a membrane electrode assembly that includes such a polymer electrolyte membrane.
A method of making a copolymer, the method comprising copolymerizing components comprising tetrafluoroethylene and at least one compound represented by formula CF2═CF—O—(CF2)a—SO2X, wherein a is a number from 1 to 4, and X is —NZH, —NZ—SO2—(CF2)1-6—SO2X′, or —OZ, wherein Z is independently a hydrogen, an alkali metal cation or a quaternary ammonium cation, and X′ is independently —NZH or —OZ, wherein the components comprise at least 60 mole % of tetrafluoroethylene based on the total amount of components, and wherein copolymerizing is carried out by aqueous emulsion polymerization at a pH of at least 9, wherein as polymerized, the copolymer has up to 400 —COOM and —COF end groups per 106 carbon atoms, wherein M is independently an alkyl group, a hydrogen atom, a metallic cation, or a quaternary ammonium cation.
Dependencies are inferred from the claim text.