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Preparation of PCU/PPy composites with self-healing and UV shielding properties

Polycarbonate-based polyurethanes (PCU) are frequently used in airship envelope materials because of its outstanding mechanical performances and aging resistance. However, the surface of PCU is likely damaged during processing and operating and the emerged minuscule cracks will lead to deterioration of perfomances for airship’s envelope materials. Herein, self-healing PCU/polypyrrole nanoparticles (PPy) composites were prepared by solution blending and quick healing of specific area for PCU was realized due to the high photo-thermal conversion merit of PPy. The results show that, the mechanical properties of PCU/PPy composites can be restored to more than 80% and the gas barrier properties can also be basically repaired when irradiating the destroyed surface using near-infrared light for only 60s. In addition, the ultraviolet visible (UV-vis) shielding performance of the PCU/PPy composites was enhanced significantly and the UV-vis transmittance was less than 14% and 2% with 0.25wt% and 0.5wt% PPy, respectively. Meanwhile when 0.25wt% PPy was added, the tensile strength increased from 17.9MPa to 21.7 MPa and the elongation at break increased from 647% to 829%. Besides, the thermal decomposition temperature at 5wt% loss increased from 277.8°C to 300.7°C and 304.88°C with 0.25 wt% and 0.5 wt% PPy, respectively. The prepared composites show promising application in aerospace domain.