Perfluoroelastomer (FFKM)

The relative inertness of fluorocarbon rubbers is provided by fluorine-carbon bonds on the elastomer backbone. Generally speaking, with increasing fluorine content, resistance to chemical attack is improved. Where fluorocarbon rubbers have a fluorine content of 63 – 68‰, the perfluorocarbons have a fluorine content of 73‰. Perfluorelastomers possess excellent resistance to extreme temperatures -26°C to +260°C (-15°F to +500°F). FFKM perfuoroelastomers offer the best chemical resistance of all elastomers.

Some types are particularly suitable for hot water, steam and hot amines. Some resist temperatures up to +326°C (+620°F). Many perfluorocarbon compounds have unusual mold shrinkage, production molds for perfluorocarbon products are different from molds for nitrile.