an ionomer and a process for forming the ionomer such that the ionomer has low equivalent weight ; below 950 , preferably between 625 and 850 , and most preferably between about 700 and about 800 ; and high conductivity , . in an alternative embodiment , the ionomer has low equivalent weight ; below 950 , preferably between 625 and 850 , and most preferably between about 700 and about 800 ; and acceptably low hydration , . these ionomers are adapted to be processed into thin films that have acceptable physical stability . they are thus extremely well - suited for low humidity or high temperature fuel cell applications .