A <scp>3D</scp> ‐dynamic networks strategy utilizing <scp> SiO ₂ </scp> ‐nanoscale ionic materials in novel waterborne polyurethane ionic nanocomposites for fast self‐healing and <scp>UV</scp> ‐blocking performance

Abstract Waterborne polyurethane (WPU) is one of the most applicable products used in various industries to manufacture smart coatings with self‐healing ability due to its being environmentally friendly. However, the self‐healable WPU coatings suffer from long healing times, low transparency, and poor physicochemical properties. Herein, ionic nanocomposite coatings were prepared based on SiO 2 ‐nanoscale ionic materials (SiO 2 ‐NIMs) and novel WPU, with fast self‐healing ability, high transparency, and UV‐blocking performance. We demonstrate that SiO 2 ‐NIMs can significantly act as a unique healing agent in the WPU due to their fluid 3D‐dynamic networks of hard core‐corona (SiO 2 ‐SO 3 − ) and soft segments (canopy). The optical micrographs show the WPU film containing 3 phr SiO 2 ‐NIMs completely repaired after 20 min at 50°C. The tensile test illustrates that elongation at break, tensile strength, and toughness values of the healed sample recovered 78.2%, 94.2%, and 69.3% of the original film, respectively. The differential scanning calorimetry, x‐ray diffraction, and dynamic mechanical‐thermal tests were applied to confirm core‐corona‐canopy segments' hardening and excellent damping behavior in the WPU matrix. The thermogravimetric and tensile analyses demonstrate that SiO 2 ‐NIMs can enhance the thermal stability and mechanical properties of WPU. This study introduces a novel strategy based on SiO 2 ‐NIMs for preparing self‐healing polymers with outstanding physicochemical properties. Highlights Synthesized novel WPU based on anionic Congo red. Introducing a novel strategy‐based SiO 2 ‐NIMs for self‐healing of coatings. Enhancement of self‐healing and thermo‐mechanical properties of the WPU. Introducing healable and UV‐blocking abilities of ionic nanocomposite coating.