PMMA/PU/CB Composite Bipolar Plate for Direct Methanol Fuel Cell

This research fabricates bipolar plates for direct methanol fuel cells (DMFC) to improve compressive strength and creep behaviour. The composites comprise of poly (methyl methacrylate) (PMMA), polyurethane (PU) and carbon black (CB) those were fabricated via bulk polymerization in a casting process. The technique can create semi-interpenetrating polymer networks (IPNs) between PMMA and PU. The composites were prepared in different weight ratios PMMA/PU/CB of 75/25_5phr, 80/20_5phr and 85/15_5phr, and their quantity of IPNs in the composites are 99.27%, 97.77% and 96.71% respectively. In terms of compressive strength values, they achieve the requirement for commercial bipolar plates which are around 60 MPa, and a total creep value is approximately 0.23% at 120 minutes, 1 kPa and 80oC. The surface and volume electrical conductivity values incorporating 5 wt% of CB are 4.25x10-7 Scm-1 and 2.05x10-6 Scm-1 respectively. The developed composite material has a suitable combination of mechanical properties and processability for DMFC bipolar plate applications.