Synthesis and characterization of epoxy with improved thermal remendability based on Diels‐Alder reaction

Abstract To produce an epoxy resin with high intrinsic self‐healing efficiency, furfurylglycidyl ether (FGE) was synthesized following a two‐step route. It carried one furan and one epoxide on each of its molecules. Having been cured using N , N ′‐(4,4′‐diphenylmethane)bismaleimide and methylhexahydrophthalic anhydride, FGE was then polymerized with two types of intermonomer linkages. That is, thermally reversible Diels–Alder (DA) bonds from the reaction between furan and maleimide groups, and thermally irreversible bonds from the reaction between epoxide and anhydride groups. These two types of bonds provide the polymer with thermal remendability and load‐bearing capacity, respectively. Compared with N , N ‐diglycidylfurfurylamine, which was previously developed by the authors and has a similar structure to FGE but with fewer furan rings, FGE can react with maleimide with lower activation energy and the DA bonds formed exhibit higher reversibility. Consequently, improved crack healability of the cured FGE characterized by nearly full recovery of fracture toughness was revealed using double cleavage drilled compression tests. Copyright © 2010 Society of Chemical Industry