PROTON EXCHANGE MEMBRANE COMPRISING FREE RADICAL SCAVENGING POLYMER

Proton exchange membranes are described. The proton exchange membranes comprise a blend of a proton-conductive polymer and a free radical scavenging polymer having phenolic hydroxyl groups. The free radical scavenging polymer and the cation exchange polymer form a miscible polymer blend with no phase separation or inorganic particle agglomeration issues. The free radical scavenging polymer may comprise a plurality of repeating units of formula (II) having phenolic hydroxyl functional groups. Membrane electrode assemblies incorporating the proton exchange membranes are also described.