Crosslinked aromatic polymer electrolyte membrane

Abstract

An aromatic polymer film substrate, or a grafted aromatic polymer film substrate having a monomer introduced therein as graft chains is irradiated with ionizing radiation to impart a crosslinked structure. The aromatic polymer film substrate or the grafted aromatic polymer film substrate, provided with the crosslinked structure, is directly sulfonated to obtain a crosslinked aromatic polymer electrolyte membrane. The crosslinked aromatic polymer electrolyte membrane has low water uptake, high proton conductivity, low methanol permeability, high chemical stability, and excellent mechanical characteristics.

1 . A crosslinked aromatic polymer electrolyte membrane comprising:
 an aromatic polymer film substrate having a crosslinked structure imparted thereto, the aromatic polymer film substrate having sulfonic acid groups introduced into aromatic rings thereof, and the aromatic polymer film substrate comprises any of polyether ether ketone, polyether imide, polyethylene naphtahlate, and liquid crystal polymer (LCP), or a composite containing any of them.   
     
     
         2 . The crosslinked aromatic polymer electrolyte membrane according to  claim 1 , wherein the aromatic polymer film substrate is a homopolymer, or has a structure having a monomer grafted to the polymer. 
     
     
         3 . The crosslinked aromatic polymer electrolyte membrane according to  claim 2 , wherein the monomer is at least one monomer selected from the group consisting of aromatic vinyl compounds, acrylic acid and derivatives thereof, acrylamides, vinylketones, acrylonitriles, vinyl fluoride-based compounds, and multifunctional monomers. 
     
     
         4 . The crosslinked aromatic polymer electrolyte membrane according to  claim 1 , wherein the crosslinked structure is a multiple-crosslinked structure.