FKM

FKM is a family of fluorocarbon-based fluoroelastomer materials defined by the ASTM International standard D1418 and ISO 1629 (ISO 1629) (both first ed. 1995 and ed. 2013). It is called FPM in some other standards, and is commonly called fluorine rubber or fluoro-rubber. All FKMs contain vinylidene fluoride as a monomer. Originally developed by DuPont (under the brand name Viton, now owned by Chemours), FKMs are today also produced by many companies, including: Daikin (Dai-El) 3M (Dyneon), Solvay S.A. (Tecnoflon), HaloPolymer (Elaftor), Gujarat Fluorochemicals (Fluonox), Zrunek (ZruElast), and several Chinese manufacturers including VSK Industrial. Fluoroelastomers are more expensive than neoprene or nitrile rubber elastomers. They provide additional heat and chemical resistance. FKMs can be divided into different classes on the basis of either their chemical composition, their fluorine content, or their cross-linking mechanism.
Types.
On the basis of their chemical composition FKMs can be divided into the following types:
Cross-linking mechanisms.
There are three established cross-linking mechanisms used in the curing process of FKMs.