Patent ID: 8609739

Claim:
A method of forming an ion conducting polymeric membrane for fuel cells, the polymeric membrane including a polymer having formula 1: wherein: Z 1 is —PO 3 H 2 ; E 1 , E 2 is an aromatic or aliphatic-containing moiety wherein E 1 and E 2 include phenylene groups such that phenylene groups in E 1 are more active towards electrophilic substitution that phenylene groups in E 2 ; a and b are each independently an integer greater than 10; n is a number equal to or greater than 1; d is an integer equal to the number of —PO 3 H 2 attached to E 1 ; P 1 , P 2 , P 3 , P 4 are each independently absent, —O—, —S—, —SO—, —SO 2 —, —CO—, —NH—, —N(R 2 )— or —R 3 —; and R 2 is C 1-25 alkyl or C 1-25 aryl; R 3 is C 1-25 alkylene, C 1-25 perfluoroalkylene, perfluoroalkyl ether, alkyl ether, or C 1-25 arylene; and Q 1 , Q 2 are each independently a fluorinated cyclobutylene-moiety, the method comprising: a) brominating a polymer having formula 2: to form a polymer having formula 3: b) phosphonating the polymer having formula 3 with a compound having formula P(OR) 3 to form a polymer having formula (4): wherein R is C 1 -C 10 alkyl and; c) hydrolyzing the polymer having formula 4 to form the polymer having formula 1; and d) forming polymer having formula 1 into a membrane for fuel cells.