Effects of Long-Term Flex-Fuel Exposure on Fluorocarbon Elastomers 900118
Long-term exposure of typical fluorocarbon elastomers in methanol fuel mixtures indicates three very important results for the automotive fuel-system design engineer:
Fluorocarbon elastomers reach an equilibrium in those solutions after a short exposure, usually within 48 hours to 1 week of initial immersion, depending upon the fuel mixture and the test temperature.
The low-temperature flexibility (as measured by TR-10) of fluorocarbon elastomers is improved by a short immersion in these fuels.
“High fluorine” (greater than 66% F) fluoroelastomers are preferable over the standard grades for their superior resistance to methanol/gasoline blended fuels over an extended term.