Epichlorohydrin is an oil resistant compound available in three formulations: as a homopolymer (CO), as a copolymer of epichlorohydrin and ethylene oxide (ECO), and as a terpolymer of epichlorohydrin, ethylene oxide, and a cure site monomer (GECO).
Epichlorohydrin combines low gas and solvent permeability with high resistance to hydrocarbon oils and fuels. Epichlorohydrin is very resistant to weathering and ozone due to complete saturation within the polymer chain.
Epichlorohydrin also remains stable during low to high temperature cycling. Because it exhibits less sub-zero stiffness, epichlorohydrin is often used in place of nitrile and chloroprene (Neoprene®) for applications requiring resistance to low temperatures.
Epichlorohydrin has only fair compression set resistance at high temperatures (i.e. 250° to 275° F).