Fluoroelastomers (FKM)
Properties and Applications
Fluoroelastomers or Fluorocarbons (FKM), also known as Viton®, are highly fluorinated polymers that are suitable for continuous use up to 230°C (445°F). Various grades are available, including copolymer and terpolymers. The most common grades consist of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride.
Fluoroelastomers have excellent heat and flame resistance, and outstanding resistance to aging, ozone, oxidizers, oils and many chemicals. They also have low gas permeability and low compression set. However, many grades have only limited low temperature performance.
FKMs are rather expensive and are, therefore, only used when components have to withstand especially harsh environments. Important applications include hoses, diaphragms, accumulator bladders, gaskets, O-rings and seals, all operating in especially demanding environments.