A tough and efficient self-healing supramolecular materials modulated with WCNT-NH₂

Self-healing polymers crosslinked by solely reversible bonds are intrinsically weaker than common covalently crosslinked networks. In this work, a self-healing materials with excellent mechanical properties was synthesized by a new design strategy, wich is to introduce covalent into reversible networks to improve its mechanical properties. First, polyamidoamine dendrimer oligomers (PAMAM-Oligomers) was synthesized. Then amine functionalized carbon nanotubes (WCNT-NH₂) reacted with PAMAM-Oligomers to form a polyamidoamine carbon nanotubes composite materials (PAMAM-WCNT-NH₂). The synthesized materials behave as rubber and exhibit spontaneous self-healing behaviour at room temperature without external stimuli. The mechanical and self-healing properties are closely related to the content of WCNT-NH2. For 0.5wt% WCNT-NH₂ in the materials, the strain of the material is 330% and tensile strength is 0.6 MPa. Importantly it can improve the self-healing efficiency to 98% of its original tensile strength in 2h.