Self-Healing Materials Formed by Cross-Linked Polyrotaxanes with Reversible Bonds

Abstract

Summary Self-healing materials based on polymer gels composed of polyrotaxane and poly(acrylamide) cross-linked with boronate linkages were synthesized and characterized. These gels combine dynamic covalent bonds with a sliding motion of functional molecules, wherein the mobility of the ring molecules along the axle in the polyrotaxane and the sliding nature of the cross-linker are thought to impart self-healing properties on the resultant materials. Both the gel state and the dried gel state exhibit rapid and efficient self-healing properties. On the basis of the self-healing property of the dried gel, a scratch-healing top coating for hard materials was prepared by a photocuring method. A coating of the self-healing material on glass demonstrates the ability to recover from a scratch mark to its initial state under semi-dry conditions.