A fluoroelastomer is a special purpose fluorocarbon

Fluorocarbon

Fluorocarbons, sometimes referred to as perfluorocarbons or PFCs, are organofluorine compounds that contain only carbon and fluorine bonded together in strong carbon–fluorine bonds. Fluoroalkanes that contain only single bonds are more chemically and thermally stable than alkanes...

-based synthetic rubber

Synthetic rubber

Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...

. It has wide chemical resistance and superior performance, especially in high temperature application in different media.

Fluoroelastomers are categorized under the ASTM D1418 & ISO 1629 designation of FKM

FKM

FKM is the designation for about 80% of fluoroelastomers as defined in ASTM D1418. Other fluorinated elastomers are perfluoro-elastomers and tetrafluoro ethylene/propylene rubbers . All FKMs contain vinylidene fluoride as a monomer...

. This class of elastomer

Elastomer

An elastomer is a polymer with the property of viscoelasticity , generally having notably low Young's modulus and high yield strain compared with other materials. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred...

s is a family comprising copolymers of hexafluoropropylene

Hexafluoropropylene

Hexafluoropropylene is a compound with the formula C3F6. It is a fluorocarbon alkene in which all of the hydrogen atoms in propylene are replaced by fluorine atoms. It is used as a chemical intermediate....

 (HFP) and vinylidene fluoride (VDF or VF2), terpolymers of tetrafluoroethylene

Tetrafluoroethylene

Tetrafluoroethylene is a chemical compound with the formula C2F4. It is the simplest alkene fluorocarbon. This gaseous species is used primarily in the industrial preparation of polymers.-Properties:...

 (TFE), vinylidene fluoride (VDF) and hexafluoropropylene

Hexafluoropropylene

Hexafluoropropylene is a compound with the formula C3F6. It is a fluorocarbon alkene in which all of the hydrogen atoms in propylene are replaced by fluorine atoms. It is used as a chemical intermediate....

 (HFP) as well as perfluoromethylvinylether (PMVE) containing specialties. The fluorine

Fluorine

Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...

 content of the most common grades varies between 66 and 70%.

Main families of polymers

• Dipolymers of VF2/HFP, like Viton
  Viton
  Viton is a brand of synthetic rubber and fluoropolymer elastomer commonly used in O-rings and other molded or extruded goods. The name is a registered trademark of DuPont Performance Elastomers L.L.C.....
  
   A and Tecnoflon: General purpose sealing. Automotive, Aerospace fuels & lubricants
• Terpolymers of VF2/HFP/TFE, like Viton B and Tecnoflon: Chemical Process plant, Power Utility Seals & Gaskets
• Terpolymers of VF2/HFP/TFE, like Viton F and Tecnoflon: Oxygenated Automotive fuels. Concentrated aqueous inorganic acids, water, steam.
• Peroxide curable polymers are similar to terpolymers. They offer better chemical resistance than corresponding terpolymers with the same fluorine percentage.
• Low temperature polymers are typically peroxide curable with an additional monomer of PMVE.

Performance

The performance of fluoroelastomers in aggressive chemicals depends on the nature of the base polymer and the compounding ingredients used for moulding the final products (e.g. O-rings, shaft seals). This performance can vary significantly when end-users purchase polymer containing rubber goods from different sources. Fluoroelastomers are generally compatible with hydrocarbons, but incompatible with ketone

Ketone

In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...

s such as acetone

Acetone

Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

 and organic acids such as acetic acid

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

.