Hierarchical Hydrogen Bonds Endow Supramolecular Polymers with High Strength, Toughness, and Self‐Healing Properties

The directional and dynamic hydrogen bonds are of vital importance for both nucleic acids and proteins, but they naturally apply strong multiple hydrogen bonds in pendant groups and weak single hydrogen bond in the backbone. The hierarchy and orthogonality of multiple and single hydrogen bonds in biological systems inspire to elegantly tailor the supramolecular polymeric materials for robust mechanical properties. Herein, this work has fabricated dynamic ultrastrong and tough supramolecular materials through bioinspired rational design of strong multiple hydrogen bonds in pendant groups and weak single hydrogen bond in the backbone. Based on quadruple hydrogen bonds of ureidopyrimidinone and single hydrogen bond of amide, the supramolecular polymer with optimized hierarchical hydrogen bonds possesses high tensile strength and strong toughness of 30.6 MPa and 74.0 MJ m−3, respectively. Meanwhile, the dynamic dissociation and reformation of the hierarchical hydrogen bonds endow the supramolecular polymer with efficient crack resistance, self‐healing, recyclability, and high energy dissipation. Flexible and self‐healing conductors can be prepared by blending the supramolecular polymer with liquid metal in a simple manner. Therefore, this work expects that the plenty of hydrogen bonding pairs in the supramolecular toolkit provide many opportunities to produce robust and tough supramolecular polymeric materials without covalent crosslinking.