Resins which may be of widely different structures but are characterized by the presence of the epoxy group. (The epoxy or epoxide group is usually present as a glycidyl ether, glycidyl amine, or as part of an aliphatic ring system. The aromatic type epoxy resins are normally used in composites.)
Synthetic resin characterized by the presence of the epoxy group, derived from petroleum products that can be cured by a catalyst or used to upgrade other synthetic resins to form a harder, more chemically resistant film. This resin possesses high mechanical strength, good adhesion, and resistance to solvents, acids, alkali, and corrosion. It usually does not weather well.