Synthesis of a diamine cross-linker containing Diels–Alder adducts to produce self-healing thermosetting epoxy polymer from a widely used epoxy monomer

A diamine cross-linker with thermal reversible Diels–Alder (DA) adducts of furan and maleimide groups has been designed and synthesised, which can be used to crosslink commercial epoxy monomers to achieve self-healing, cross-linked epoxy polymers. This new strategy to make self-healing epoxy polymer was successfully proved by incorporating the cross-linker with a widely used epoxy monomer, the diglycidyl ether of bisphenol A. The self-healing property of the new epoxy polymer was shown by complete elimination of cracks after the process of retro-DA and DA reactions which occurred in the cross-linker component of the network.