Presently described is a monomer having the formula:

##STR00001##

wherein n ranges from 2 to 8; Y is F or C.sub.mF.sub.2m+1; a is 0, or averages 1 to 2; m is independently 1, 2, 3, or 4; and X is F or OH.

Also described is a method of making such monomer, various compounds prepared during while making the monomer, fluoropolymers comprising polymerized units of such monomer, fuel cell membranes, membrane electrode assemblies, and methods of making fluoropolymers.

Presently described is a monomer having the formula:

##STR00001##

wherein n ranges from 2 to 8; Y is F or C.sub.mF.sub.2m+1; a is 0, or averages 1 to 2; m is independently 1, 2, 3, or 4; and X is F or OH.

Also described is a method of making such monomer, various compounds prepared during while making the monomer, fluoropolymers comprising polymerized units of such monomer, fuel cell membranes, membrane electrode assemblies, and methods of making fluoropolymers.

An electrolyte membrane is described that has improved bondability with a catalyst layer and that achieves good power generation performance, without the electrolyte membrane undergoing a physical treatment and without any loss of surface modification effect, where the electrolyte membrane comprises a polymer electrolyte and a nonionic fluorochemical surfactant.

An electrolyte membrane is described that has improved bondability with a catalyst layer and that achieves good power generation performance, without the electrolyte membrane undergoing a physical treatment and without any loss of surface modification effect, where the electrolyte membrane comprises a polymer electrolyte and a nonionic fluorochemical surfactant.

The present disclosure relates to a polymer electrolyte membrane comprising a polymer membrane containing an ion conductor, and a plurality of composite fibers, wherein the composite fiber comprises a core portion continuously formed in the longitudinal direction of the composite fiber and a matrix portion surrounding the core portion, and the core portion contains an ion exchange functional group.

Disclosed is a method of producing an antioxidant that has excellent antioxidant ability and is well dispersed when applied to a membrane-electrode assembly (MEA). The method includes a step of preparing a powder including reduced metal oxide and a step of mixing the powder with a powdery ionomer to obtain an antioxidant in which the ionomer is bound to the surface of the reduced metal oxide.

Disclosed is a method of producing an antioxidant that has excellent antioxidant ability and is well dispersed when applied to a membrane-electrode assembly (MEA). The method includes a step of preparing a powder including reduced metal oxide and a step of mixing the powder with a powdery ionomer to obtain an antioxidant in which the ionomer is bound to the surface of the reduced metal oxide.

A polymer electrolyte membrane includes an ion-conducting polymeric electrolyte material and platelets, distributed through the polymeric electrolyte material. The platelets have an aspect ratio of length to thickness of at least 2:1. The platelets are aligned generally parallel to a length of the membrane. The platelets can be functionalized with free radical scavengers, or other moieties, to extend the lifetime of the membrane or of a membrane electrode assembly incorporating the membrane.

A polymer electrolyte membrane includes an ion-conducting polymeric electrolyte material and platelets, distributed through the polymeric electrolyte material. The platelets have an aspect ratio of length to thickness of at least 2:1. The platelets are aligned generally parallel to a length of the membrane. The platelets can be functionalized with free radical scavengers, or other moieties, to extend the lifetime of the membrane or of a membrane electrode assembly incorporating the membrane.

A polymer electrolyte membrane according to the present invention has a cluster diameter of 2.96 to 4.00 nm and a converted puncture strength of 300 gf/50 μm or more. The polymer electrolyte membrane according to the present invention has a low electric resistance and an excellent mechanical strength.