Patent ID: 11155661

Abstract:
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.