Silane crosslinked structure-introduced fuel-cell polymer electrolyte membrane and fuel-cell electrode assembly having the same

A process for producing a polymer electrolyte membrane for a fuel cell, the process comprising in sequence:

• forming graft molecular chains by graft-polymerization of a vinyl silane coupling agent to a polymer film substrate, the vinyl silane coupling agent having phenyl groups capable of holding sulfonic acid groups;
• introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains;
• and hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains.

A process for producing a polymer electrolyte membrane for a fuel cell, the process comprising in sequence:

• forming graft molecular chains by graft-polymerization of a vinyl monomer solution on a polymer film substrate, the vinyl monomer solution containing a vinyl silane coupling agent having phenyl groups capable of holding sulfonic acid groups;
• hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains;
• and introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains.

A process for producing a polymer electrolyte membrane for a fuel cell, the process comprising in sequence:

• forming graft molecular chains by graft-polymerization of a vinyl monomer solution on a polymer film substrate, the vinyl monomer solution being composed of a vinyl monomer having phenyl groups capable of holding sulfonic acid groups, and a vinyl silane coupling agent containing no phenyl group;
• introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains;
• and hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains.

A process for producing a polymer electrolyte membrane for a fuel cell, the process comprising in sequence:

• forming graft molecular chains by graft-polymerization of a vinyl monomer solution on a polymer film substrate, the vinyl monomer solution being composed of a vinyl monomer having phenyl groups capable of holding sulfonic acid groups, and a vinyl silane coupling agent containing no phenyl group;
• hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains;
• and introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains.