Graphite/epoxy composites have the potential to be used as conductive polymer composites (CPCs). Nevertheles, graphite/epoxy composites have a low in-plane conductivity, so a large amount of conductive filler is needed to increase the in-plane conductivity. However, other composite properties can be affected if the conductive filler content is too high. The casting method was used to produce graphite/epoxy composites in this study. Graphite was added to an epoxy resin at various weight percentage (wt%), curing times, and curing temperatures. The result show that a graphite/epoxy composite with 80 wt% of graphite at curing temperature of 130 ℃ and a curing time of 120 minutes produce the highest in-plane conductivity and shore hardness of 28 S/cm and 94.88 SHD, respectively. In contrast, the highest tensile strength of the graphite/epoxy composite (18.5 N/mm²) was obtained with 65 wt% of conductive filler material, the lowest amount considered in this study. This is due to the reduced ability of epoxy resins to bind to higher amounts of conductive fillers (e.g., 80 wt%).

Carbon nanotubes (CNTs) have a huge potential as conductive fillers in conductive polymer composites (CPCs), particularly for bipolar plate applications. These composites are prepared using singlefiller and multifiller reinforced multiwalled carbon nanotubes (MWCNTs) that have undergone a chemical functionalization process. The electrical conductivity and mechanical properties of these composites are determined and compared between the different functionalization processes. The results show that UV/O₃‐treated functionalization is capable of introducing carboxylic functional groups on CNTs. Acid‐treated CNT composites give low electrical conductivity, compared with UV/O₃‐treated and As‐produced CNTs. The in‐ and through‐plane electrical conductivities and flexural strength of multifiller EP/G/MWCNTs (As‐produced and UV/O₃‐treated) achieved the US Department of Energy targets. Acid‐treated CNT composites affect the electrical conductivity and mechanical properties of the nanocomposites. These data indicate that the nanocomposites developed in this work may be alternative attributers of bipolar plate requirements.