In Situ Anchoring Functional Molecules to Polymer Chains Through Supramolecular Interactions for a Robust and Self‐Healing Multifunctional Waterborne Polyurethane

Abstract Nowadays, much attention is paid to the development of high‐performance and multifunctional materials, but it is still a great challenge to obtain polymer materials with high mechanical properties, high self‐healing properties, and multifunctionality in one. Herein, an innovative strategy is proposed to obtain a satisfactory waterborne polyurethane (PMWPU‐Bx) by in situ anchoring 3‐aminophenylboronic acid (3‐APBA) in a pyrene‐capped waterborne polyurethane (PMWPU) via supramolecular interactions. The multiple functional sites inherent in 3‐APBA can produce supramolecular interactions with groups on PMWPU, promoting the aggregation of hard domains in the polymer network, which confers the PMWPU‐Bx strength (7.9 MPa) and high modulus (243.2 MPa). Meanwhile, the dynamic natures of boronic ester bonds formed by the condensation of 3‐APBA endow PMWPU‐Bx with a high self‐healing efficiency. Additionally, PMWPU‐Bx exhibits fluorescence tunability due to the controlled π–π stacking. In this research, the strategy of anchoring functional molecules onto polymers through supramolecular interactions synchronously achieves the high performance and the multi‐functionality of waterborne polyurethanes, but also broadens their potential applications in the fields of optical anticounterfeiting and encrypted information transmission.