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

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.