Fire-safe, mechanically strong and tough thermoplastic Polyurethane/MXene nanocomposites with exceptional smoke suppression

Thermoplastic polyurethane (TPU) has been extensively used in many industrial fields because of its excellent mechanical, electrically insulating and chemical/oil-resistant properties. However, it is inherently flammable and produces a huge amount of heat and smoke upon ignition, significantly impeding its industrial applications. Current fire-retardant strategies often result in significantly reduced flam-mability, but limited contribution to smoke suppression, and even reduced mechanical properties due to different governing mechanisms. To overcome this hurdle, herein, we reported a titanium carbide-derived nanohybrid (Ti3C2Tx-D-H) via simple hydrogen-bonding assembly. Our results show that the peak of heat release rate and total smoke release yield of TPU nanocomposite containing 2.0 wt% Ti3C2Tx-D-H are decreased by 27.3% and 43.8%, respectively, compared to those of pure TPU. Besides, the resultant TPU nanocomposite shows 32.8% and 56.8% increases in tensile strength and toughness, respectively. The distinguished fire-resistance and mechanical performances are ascribed to the tortuous effect, catalyzed charring and free radicals quenching function of Ti3C2Tx-D-H nanohybrid together with a favorable TPU-Ti3C2Tx-D-H interface. This work offers a promising strategy for simultaneously enhancing the fire resistance, smoke suppression and mechanical robustness of TPU, which is expected to find more in-dustrial applications. (C) 2022 Elsevier Ltd. All rights reserved.