Benzoxazine-Based Thermoset with Autonomous Self-Healing and Shape Recovery

A novel approach is reported for self-healing of polybenzoxazine thermosets based on both supramolecular attractions and metal–ligand interactions. The relating smart material was synthesized by using bis(3-aminopropyl)-terminated polydimethylsiloxane, formaldehyde, and bisphenol A. The films of the obtained main-chain polybenzoxazine precursor (Poly(Si-Bz)) containing 2% FeCl3 were prepared and cured at low temperatures (100–120 °C). The structures of the precursors and final products were characterized by spectral analysis. The curing and thermal stability of the related materials were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Self-healing efficiency was studied by stress–strain measurements. Potential shape recovery (SR) behavior was also demonstrated by preparing curled or spiral fixed shapes, and the transformation of temporary shapes to these fixed shapes was verified.