Chris Janke

Compatibility of elastomers with test fuels of gasoline blended with ethanol

This article summarises the compatibility of six elastomers – used in fuel storage and delivery systems – with test fuels representing gasoline blended with up to 85% ethanol. Individual coupons were exposed to test fuels for four weeks to achieve saturation. The change in volume and hardness, when wetted and after drying, were measured and compared with the original condition.

Compatibility Assessment of Elastomeric Infrastructure Materials with Neat Diesel and a Diesel Blend Containing 20 Percent Fast Pyrolysis Bio-oil

The compatibility of elastomer materials used in fuel storage and dispensing applications was determined for an off-highway diesel fuel and a blend containing 20% bio-oil (Bio20) derived from a fast pyrolysis process. (This fuel blend is not to be confused with B20, which is a blend of diesel fuel with 20% biodiesel.) The elastomer types evaluated in this study included fluorocarbon, fluorosilicone, acrylonitrile rubber (NBR), styrene butadiene rubber (SBR), polyurethane, neoprene, and silicone. All of these elastomer types are used in sealing applications, but some, like the nitrile rubbers are also common hose materials. The elastomer specimens were exposed to the two fuel types for 4 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 65 hours at 60°C and then remeasured. A solubility analysis was performed to better understand the performance of plastic materials in fuel blends composed of bio-oil and diesel. All of the elastomers exhibited higher solubility (volume swell) with the Bio20 fuel blend consistent with a solubility assessment. However, many of the elastomers (except neoprene, SBR, and silicone) exhibited very little swelling with exposure to the baseline diesel which was not predicted in the solubility study. When dried, those elastomer specimens that swelled when immersed in the test fuel, remained swollen (albeit to a lesser degree) when dried. All of the elastomers showed the highest extent of swelling with Bio20 (even when compared to specimens exposed to ethanol-blended gasoline test fuels). The lone exception was silicone which exhibited lowered volume expansion in diesel and Bio20 than in ethanol-blended gasoline. Even fluorocarbon, which is rated as highly compatible in most fuel types, swelled over 60% when exposed to Bio20. The bio-oil used in this study, like most bio-oils contained appreciable levels of ketones and phenols. The compounds are notorious solvents for many elastomers and likely contributed to the observed volume expansions. CITATION: Kass, M., Janke, C., Connatser, R., Lewis, S. et al., Compatibility Assessment of Elastomeric Infrastructure Materials with Neat Diesel and a Diesel Blend Containing 20 Percent Fast Pyrolysis Bio-oil, SAE Int. J. Fuels Lubr. 8(1):2015, doi:10.4271/2015-01-0888. 2015-01-0888 Published 04/14/2015 Copyright

Compatibility Assessment of Plastic Infrastructure Materials with Test Fuels Representing E10 and iBu16

The compatibility of plastic materials used in fuel storage and dispensing applications was determined for a test fuel representing gasoline blended with 10% ethanol. Prior investigations were performed on gasoline fuels containing 25, 50 and 85% ethanol, but the knowledge gap existing from 0 to 25% ethanol precluded accurate compatibility assessment of low level blends, especially for the current E10 fuel (gasoline containing 10% ethanol) used in most filling stations, and the recently accepted E15 fuel blend (gasoline blended with up to15% ethanol). For the majority of the plastic materials evaluated in this study, the wet volume swell (which is the parameter most commonly used to assess compatibility) was higher for fuels containing 25% ethanol, while the volume swell accompanying E10 was much lower. However, several materials, such as polyvinylidene fluoride (PVDF), fiberglass resins, and the polyethylene terephthalate co-polymer (PETG) exhibited similar volume expansions with both 10 and 25% ethanol. In the second part of this study, the compatibility performance of the infrastructure plastics in the E10 test fuel was compared to a test fuel containing 16% isobutanol (which has the same oxygen level as E10). The measured property changes (volume and hardness) in these two fuels were similar for the majority of the plastics tested. However, Nylon 6, Nylon 6,6, and the vinyl ester fiberglass resin showed much better compatibility with a 16% isobutanol blend than with a blend containing 10% ethanol. CITATION: Kass, M., Janke, C., Theiss, T., Baustian, J. et al., Compatibility Assessment of Plastic Infrastructure Materials with Test Fuels Representing E10 and iBu16, SAE Int. J. Fuels Lubr. 8(1):2015, doi:10.4271/2015-01-0894. 2015-01-0894 Published 04/14/2015 Copyright

Compatibility Assessment of Elastomer Materials to Test Fuels Representing Gasoline Blends Containing Ethanol and Isobutanol

The compatibility of elastomeric materials used in fuel storage and dispensing applications was determined for test fuels representing neat gasoline and gasoline blends containing 10 and 17 vol.% ethanol, and 16 and 24 vol.% isobutanol. The actual test fuel chemistries were based on the aggressive formulations described in SAE J1681 for oxygenated gasoline. Elastomer specimens of fluorocarbon, fluorosilicone, acrylonitrile rubber (NBR), polyurethane, neoprene, styrene butadiene rubber (SBR) and silicone were exposed to the test fuels for 4 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 20 hours at 60°C and then remeasured for volume and hardness. Dynamic mechanical analysis (DMA) was also performed to determine the glass transition temperature (T g ). Comparison to the original values showed that all elastomer materials experienced volume expansion and softening when wetted by the test fuels. The fluorocarbons underwent the least amount of swelling ( 100%). The level of swelling for each elastomer was higher for the test fuels containing the alcohol additions. In general, ethanol produced slightly higher swell than the oxygen equivalent level of isobutanol. When dried, the fluorocarbon specimens were slightly swollen (relative to the baseline values) due to fuel retention. The NBRs and neoprene exhibited shrinkage and embrittlement associated with the extraction of plasticizers. SBR also experienced shrinkage (after drying) but its hardness returned to the baseline value. The dried volumes (and hardness values) of the silicone, SBR and fluorosilicone rubbers closely matched their original values, but the polyurethane specimen showed degradation with exposure to the test fuels containing ethanol or isobutanol. The DMA results showed that the test fuels effectively decreased T g for the fluorocarbons, but increased T g for the NBR materials. The T g values other elastomers were not affected by the test fuels.

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Complete braided adsorbent for marine testing to demonstrate 3g-U/kg-adsorbent

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