Highly conductive molding compounds and fuel cell bipolar plates comprising these compounds

Abstract

A conductive polymer is disclosed which is suitable for use in applications which require corrosion resistance including resistance to corrosion when subjected to acidic flow at temperature ranging from −40 to 140 degrees Fahrenheit and which can be molded into highly intricate and thin specimens which exhibit consistent conductivity, sufficient strength and flexibility, and appropriate surface characteristics. In particular the invention involves molding unsaturated prepolymer resin composition which have high loadings of conductive fillers. Further to enable the necessary characteristics, the compositions include rheological modifiers such as Group II oxides and hydroxides; carbodiamides; aziridines; polyisocyanates; polytetrafluoroethylene (PTFE); perfluoropolyether (PFPE), and polyethylene. Ostensibly, these modifiers act to alter the apparent molecular weight and three dimensional prepolymer network structures correcting rheological deficiencies which otherwise lead to excessive resin particulate separation during the molding process and large variances in bulk conductivity across the plate surface. The composition is disclosed for use in electrochemical cells, such as fuel cells.