Most commercial perfluoroelastomers are terpolymers of tetrafluoroethylene (TFE), perfluoromethylvinyl ether (PMVE), and a cure site monomer (CSM). The fully-fluorinated monomers contained in perfluoroelastomers are the reason they exhibit superior chemical resistance. As with fluorocarbon elastomers, the bonds between carbon and fluorine atoms are extremely strong, making the chemical structure virtually unbreakable. Also, polymers with high levels of fluorine (as opposed to hydrogen) have proven to be more stable and less chemically reactive. Perfluoroelastomers also enjoy immunity from chemical attack due to saturation along the polymer’s backbone. There are no double bonds to be attacked by degradants such as oxygen, ozone, UV light, or harsh chemicals.
Perfluoroelastomers can trace their lineage back to the late 1960s, when chemists at DuPont pioneered what came to be known as Kalrez®. In so doing, they combined the chemical resistance of polytetrafluoroethylene (Teflon®) and the elasticity of flouroelastomer (Viton®) into a fully-fluorinated polymer that could be cross-linked. Differences in perfluoroelastomer performance are often due to the manner in which the material is cross-linked.