The present invention is a grafted polymer electrolyte membrane prepared by
first preparing a precursor membrane comprising a polymer which is capable
of being graft polymerized, exposing the surface of the precursor membrane
to a plasma in an oxidative atmosphere, then graft-polymerizing a side
chain polymer to the plasma treated precursor membrane and introducing a
proton conductive functional group to the side chain. The resulting
grafted polymer electrolyte membrane has excellent stability and
performance when used in a proton-exchange membrane fuel cell or for
electrolysis of water.
