NIR induced self-healing polyurethane/polypyrrole nanocomposites.

Polypyrrole nanoparticles (PPy) are widely used in cancer treatment because of its excellent photo-thermal effect. To our best knowledge, the application of such property in self-healing polymers have rarely been reported. Here, thermoplastic polyurethanes (TPU) were prepared by two-step method, and then TPU/PPy nanocomposites were prepared by solution blending. The stress and strain of TPU were increased from 8.20 MPa to 1540% to 13.50 MPa and 1650% with 0.25 wt% PPy respectively. Meanwhile, the thermal stability was also improved significantly. After the composite film was cut and spliced together, the fracture was irradiated with NIR, the mechanical strength of the composite material could be restored to over 80% in only 30 s. The strengthening effect of PPy in polyurethane and the rapid repair performance of composite materials can well solve the contradiction that self-repairing materials cannot improve the repair efficiency and mechanical properties simultaneously, and at the same time broaden the application area of PPy. Polypyrrole (PPy) can well disperse in polyurethane, which significantly improve the mechanical properties and thermal stability of composites. Meanwhile, the material can be repaired quickly under near-infrared light (NIR). Image 1 • PPy are used in NIR light-induced self-healing materials. • PPy can enhance mechanical strength and thermal stability of TPU. • PPy can promote the crystallization of TPU. • TPU/PPy nanocomposites can be repaired quickly under NIR. [ABSTRACT FROM AUTHOR]