Thermo-reversible MWCNTs/epoxy polymer for use in self-healing and recyclable epoxy adhesive

A self-healing and recyclable carbon tube/epoxy adhesive was prepared by epoxy monomer with Diels-Alder (DA) bonds, diethylenetriamine and polyethyleneimine modified multi-wall carbon nanotubes (MWCNTs). The self-healing and recyclable ability was attained by thermally reversible Diels-Alder reaction between furan and maleimide in the epoxy monomer. By controlling the molar ratio of furfuryl glycidyl ether and 4,4′-methylenebis(N-phenylmaleimide), the glass transition temperature and mechanical properties of MWCNTs/epoxy adhesives were varied. The self-healing properties of MWCNTs/epoxy polymers were evaluated by lap shear experiment and the results showed that the MWCNTs/epoxy adhesives exhibited enhanced mechanical properties and excellent self-healing ability under heat stimulus. The healing efficiency was related to the molecule mobility and the conversion of DA reaction between furan and maleimide. The MWCNTs/epoxy adhesives also displayed excellent recyclable ability by transforming into soluble polymer under heating. These materials offer a wide range of possibilities to produce materials with healing and recyclable ability and have the potential to bring great benefits to our daily lives by enhancing the safety, performance, and lifetime of products.