Tunable CO ₂ ‐Derived Ionic Polyureas for Strong and Multifunctional Adhesion

ABSTRACT Conventional adhesives face an inherent trade‐off between strong cohesion and effective interfacial bonding. This study introduces a platform of CO 2 ‐derived ionic polyureas (IPUas) that overcome this conflict and advance sustainable chemistry. By strategically tuning the ionization degree of a polyurea backbone, it shows that ionic moieties disrupt the dense internal hydrogen‐bond network to liberate urea groups for substrate interaction, while establishing a reinforcing electrostatic network for cohesion. At an optimal ionization of 40% with TFSI − as the anion, this synergy yields an exceptional adhesion strength of 17.8 MPa, about a 13‐fold enhancement over its non‐ionic counterpart. Side‐chain engineering and anion exchange further direct adhesion behavior and impart advanced functionalities, including electro‐responsiveness, fluorescence, and exceptional tolerance to solvents, water, and cryogenic conditions. This study provides a foundational design principle for unifying supreme adhesive performance, intelligent multifunctionality, and environmental sustainability, paving the way for next‐generation adhesives in demanding and adaptive applications.