Strong, Reusable, and Self‐Healing Lignin‐Containing Polyurea Adhesives

Abstract Reusable, self‐healable, removable, and strong bio‐based polyurea adhesives were successfully synthesized via partially substituting polyetheramine with polyetheramine‐grafted lignin and introducing a chain extender containing dynamic disulfide bonds. The polyetheramine‐grafted lignin endowed the polyurea adhesives with significantly enhanced adhesion strength on either metal or wood substrates by introducing intensive hydrogen bonding interactions; the dynamic disulfide bonds played a key role in the excellent self‐healing and reusable performance. The thermostability of polyurea adhesives was also improved by introducing lignin. This work provides a novel approach for the high‐value utilization of low‐cost lignin in recyclable adhesives with excellent comprehensive performance.