Recent breakthrough technologies in hydrogen gas (H2) fuel cell design have led to compact light-weight construction suitable for automotive designs. As an example, the Toyota Mirai FCV (Fuel Cell Vehicle) is the showcase of this new technology. It uses low temperature polymer electrolyte membranes (PEMs). PEMs operate at pressures ranging from near ambient to about 700 kPa (7 atm) and at temperatures between 50 and 90°C. The underlying reason for these conditions is due to Fick’s law which establishes that the higher the pressure gradient the higher the diffusion rate through a membrane, and the more hydrogen pushed through the PEM, the more power that can be generated (watts of electricity produced by the cell). What is true for the membranes that create the power is also true for the hydrogen supply and distribution systems. Permeation loss through the hoses and seals is a loss of flammable and expensive hydrogen fuel. This leads to safety concerns and lowers the efficiency of electrical power generation.
In consideration of hydrogen sealing regarding automotive refueling, storage, supply, and the PEM systems (onboard and offboard), a study using response surface graphs will show the N-990 filler ratio to total filler loading across common permeation resistant polymer of brominated-butyl (with a resin or sulfur curing system) to provide a comparative evaluation of performance. Elastomer formulation optimization will highlight hydrogen low permeation performance. Testing will follow ASTM D1434 guidelines for steady state permeation analysis and will evaluate hydrogen gas at 90 °C and 700 kPa for an 8hrs measurement duration after equilibrium is reached.