A stretchable and rapidly self-healable polysiloxane elastomer based on reversible aluminum-amino coordination

Self-healing polymers have been increasingly investigated for the development of sustainable materials. However, it is challenging for self-healable systems to achieve a rapid self-healing at low temperature. Here, we sought to introduce weaker yet more dynamic supramolecular interactions to construct self-healable elastomers. By incorporating main-group aluminum ions into an amino-grafted polysiloxane matrix, a supramolecular elastomer, PDMS-NH2-Al, was obtained. Unlike most reported strong coordination systems based on transition/rare-earth metals and pi-acid ligands, the coordination between main-group Al3+ and simple sigma ligands (amines) was revealed to be comparatively weaker yet more dynamic. This unique combination led to an excellent healing efficiency over 90% in 60 min even at a temperature as low as -20 degrees C.