Octopus sucker-inspired hierarchical structure MXene@carbon nanotubes enhancing the mechanical properties and fire safety of thermoplastic polyurethane composites through the interfacial engineering

• The octopus sucker-inspired M@CN with hierarchical structure is successfully synthesized. • The Interface engineering between M@CN and TPU matrix is greatly improved. • TPU/M@CN demonstrates superior improvement of TS of 79.5% and EB of 113.5%. • The pHRR and smoke suppression of TPU/M@CN-3 are reduced by 54.1% and 40.4%, respectively. Developing high-performance polymer materials with excellent mechanical properties and fire safety in fires remains a thorny challenge. In this article, hierarchical structure MXene@carbon nanotubes (M@CN) are prepared through electrostatic interactions for enhancing the interfacial engineering of thermoplastic polyurethane (TPU). With biomimetic method, the TPU/M@CN-3 nanocomposites performed octopus sucker-inspired structure during the stretching behavior, making the tensile strength and elongation at break of TPU/M@CN-3 increase 79.5% and 113.5%, respectively. What’s more, thanks to the 1D-2D hierarchical structure of M@CN, fire safety of these TPU nanocomposites were extremely reinforced. Compared with the pure TPU, the TPU/M@CN-3 of peak heat release rate (pHRR) and smoke density max (Ds max) reduced by 54.1% and 40.4%. The production rates of carbon monoxide (CO) and carbon dioxide (CO 2 ) were reduced by 62.7% and 33.0%, respectively. Therefore, this work provides a convenient way to prepare a high-performance TPU with highly mechanical properties and fire safety through enhacing the interfacial engineering.