Synthesis of bisphenol A diglycidyl ether The commonest epoxy resins are based upon reacting epichlorohydrin (ECH) with bisphenol A,  leading to a distinct chemical substance referred to as bisphenol A diglycidyl ether (usually often called BADGE or DGEBA).Epoxy resins are polymeric or semi-polymeric components or an oligomer, and therefore not of