Thermal driven self-healing infrared and heat shielding composites based on reversible Diels-Alder reaction

摘要

Infrared and heat shielding materials have a wide range of applications in military infrared invisibility and thermal insulation for energy saving, but mechanical damage during use may reduce the service life. In this study, waterborne polyurethanes/gallium tin oxide (WPU/GTO) composites with good infrared and thermal shielding capabilities were fabricated after the introduction of GTO nanoparticles into the thermal driven self -healing WPU matrix. The results showed that the WPU/GTO composite films can show good healing effi-ciency through thermally reversible DA reactions, with a self-healing efficiency of 80 % in 30 min at 120 degrees C. In addition, the presence of GTO gives the composite good thermal shielding properties without affecting its thermal stability. Due to free carrier absorption and plasma reflection, the resulting composite films containing 1 wt% GTO could shield from approximately 95 % of infrared light, with an insulation temperature difference of 15 degrees C when compared to pure polyurethane. This work provides a feasible solution for the preparation of infrared and heat shielding materials with self-healing capabilities.

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