Description
Fluorocarbon (or FKM) rubber is a widely used, premium grade compound especially well suited to applications where prolonged exposure to petroleum oils at high operating temperatures is encountered. Such properties make it especially useful in automotive "under-hood" applications. Additionally, FKM is particularly resistant to swell in the highly aromatic, non leaded, additive loaded gasoline mandated by environmental regulations today. Its low temperature deficiencies can be overcome somewhat by special compounding. Fluorine content is generally in the 66% to 70% range. Fluorocarbon rubber is exceptionally resistant to embrittlement when exposed to high heat over long periods of time; it is considered to be serviceable indefinitely when exposed continuously to 200°C. The cure system of choice for most fluorocarbon compounds is bisphenol, as it provides the best combination of compression set and improved steam and acid resistance. Diamine and peroxide cure systems can also be employed. Fluorocarbon vulcanizates are very resistant to ozone and and atmospheric aging.
Composition
Fluorocarbon Rubber
Physical Properties*
| |
Excellent |
Good |
Fair |
Poor |
| Abrasion resistance |
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• |
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| Compression Set |
• |
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| Elongation |
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• |
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| Flame resistance |
• |
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| Gas permeability |
• |
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| Low temperature flexibility |
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• |
| Tear resistance |
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|
• |
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| Tensile strength |
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• |
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Chemical Resistance*
| |
Excellent |
Good |
Fair |
Poor |
| Anhydrous ammonia |
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|
|
• |
| Dilute acids |
• |
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| Dilute alkalis |
• |
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| Ketones |
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• |
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| Ozone |
• |
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| Petroleum oils |
• |
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| Solvents |
• |
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| Steam |
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|
• |
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| Water |
• |
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| Weather |
• |
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Operating Temperature
-15 to 400 °F
*Excellent, good, fair and poor are intended to serve as general guidelines only. Actual testing in the application environment is always recommended. |
