Abstract: Fluid diffusion layers with favorable mechanical, physical and structural properties are prepared for fuel cell electrodes by: impregnating a porous carbonaceous web with a matrix comprising a polymer having pyrrolidone functionality and a high carbon char yield resin, such as activated aramid fiber pulp, lignins, phenolics, benzoxazines and phthalonitriles; and carbonizing the matrix. The polymer is optionally oxidized before carbonizing. The matrix may also include conductive fillers and/or pore formers. The fluid diffusion layers are particularly suitable for use in continuous roll-to-roll MEA processing of GDLs for use in solid polymer electrolyte fuel cells operating at high current densities and/or in highly humidified conditions.

Abstract: A carbon friction material, preferably a woven carbon friction material, wherein a binder such as an epoxy or phenolic resin is used to strengthen and impart rigidity to the friction material. The friction material has a graded concentration of the binder such that the friction surface may have substantially no binder. A reinforcing substrate such as a fiberglass backing may also be present. The coefficient of friction at the friction surface may be further increased by, for example, shaving the surface such that a plurality of fibers become oriented in a direction perpendicular to the friction surface.