Patent ID: 8383763

Claim:
A proton exchange membrane comprising a sulfonated copolymer having the chemical structure: wherein: n/(n+m) ranges from about 0.001 to about 1; Y is selected from the group consisting of —S—, S(O)—, —S(O) 2 —, —C(O)—, —P(O)(C 6 H 5 )—, and combinations thereof; and Z is selected from the group consisting of a direct carbon-carbon single bond, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —C(CF 3 )(C 6 H 5 )—, —C(O)—, —S(O) 2 —, and —P(O)(C 6 H 5 )—.