Testing the Effects of a Bio-Derived Alternative Aviation Gasoline on Aircraft Materials In Comparison to 100 Low Lead Aviation Gasoline

Within the past decades, there has been increasing interest in alternative fuels in the aviation industry. However for these alternative fuels to be accepted they must show they do not affect materials, particularly elastomers, in aircraft significantly different than standard 100 low lead (100LL). This research is focused on comparing the effects of a proprietary bio-derived alternative fuel on elastomers against 100LL. Materials to be tested are Buna-N vinyl, neoprene, nitrile, plain cork, neoprene and cork (backed cork), Viton, high-purity silicone, polyester, polysulfide and rubber hose. The testing to be performed includes volume swell, tensile strength, elongation, durometer hardness and density. The samples were soaked in fuel for a period of 28 days at room temperature, 71°C and 93°C. All testing will be done in accordance with respective ASTM standards. Due to proprietary concerns, actual measurement cannot be reported, but differences between the two fuels can, i.e. the percentage difference between materials soaked in 100LL and the bio-derived alternative. Statistical methods were applied to the volume change, tensile strength and elongation tests to determine significant differences. The largest difference in volume swell was for backed cork, the largest difference in tensile and elongation was in neoprene, the largest difference in density was in nitrile, and plain cork exhibited the largest difference in durometer hardness. Viton and polyester exhibited no significant differences. Limited testing conducted with a second bio-derived alternative showed polysulfide as having the greatest difference between the two bio-derived fuels.