Epoxy resins or epoxies are organic compounds that can be hardened into adhesive materials with excellent thermal stability, mechanical strength, and chemical resistance. The hardening or ‘curing’ results from cross-linking either within the resin itself or between the resin and a co-reactant. Epoxies are produced by polymerization of epoxides—organic molecules with one or more three-atomic, triangluar carbon–oxygen–carbon (C–O–C) rings. Such rings exhibit a high strain, resulting in the easy polymerization of epoxies.