NIR Light Stimulated Self‐Healing Reduced Tungsten Oxide/Polyurethane Nanocomposite Based on the Diels−Alder Reaction.

Cracks formed in materials can influence the performances and shorten their lifetime. Self‐healing materials can repair cracks caused by mechanical damage using external stimuli, which increases their safety, extend their service life, and can save renovation costs. In this work, a novel thermo‐responsive linear Diels‐Alder polyurethane (DAPU) and reduced tungsten oxide (WO3−x) (W‐DAPU) is developed for the first time. Its near‐infrared (NIR) light‐induced self‐healing properties are evaluated using qualitative optical observation and quantitative tensile measurements. The NIR light‐induced self‐healing and photothermal conversion property of W‐DAPU is also systematically investigated. The results show that linear DAPU has an excellent thermo‐reversible self‐healing efficiency of 94.8% and heals within 6 s due to the presence of a DA bond. In addition, the W‐DAPU has a self‐healing efficiency of 83.2% with outstanding photothermal conversion. This study paves the way to design and fabricate stimuli‐responsive nanocomposite materials for various applications. [ABSTRACT FROM AUTHOR]