Functionalizing MXene towards highly stretchable, ultratough, fatigue- and fire-resistant polymer nanocomposites.

[Display omitted] • A multifunctional MXene-based hybrid (Zr-MXene) has been prepared. • 1 wt% of Zr-MXene increases ductility and toughness of TPU by 33% and 88%, respectively. • 1 wt% of Zr-MXene increases the tensile strength and fatigue resistance of TPU. • The addition of Zr-MXene significantly reduce the flammability of TPU. • The peak heat release rate and peak smoke production rate are respectively reduced by 63% and 56%. Thermoplastic polyurethane (TPU) features many important industrial applications, but intrinsic flammability extremely impedes its practical applications. Current fire-retardant strategies often lead to improved flame retardancy but reduced mechanical properties (strength, ductility, and toughness). Hence, to date it has been unsuccessful to design advanced TPU materials that are strong, stretchable, tough, fatigue-and fire-resistant to meet increasing performance portfolio requirements. Here, we report a hybridized fire retardant (Zr-MXene) by in situ facilely loading zirconium amino-tris-(methylenephosphonate) (Zr-AMP) onto the titanium carbide (MXene) surface. Our results show that with 1 wt% of Zr-MXene, the resultant TPU nanocomposites demonstrate a record break strain (2060%) and toughness (316 MJ/m3) to date, in addition to increased tensile strength by 43.4% and improved fatigue resistance relative to the TPU matrix, because of favorable interfacial hydrogen-bonding. Moreover, the resultant TPU material exhibit significantly reduced flammability as a result of the combined physical barrier, catalytical carbonization and diluting effects of Zr-MXene. This work provides a promising strategy for the creation of multifunctional MXene and its polymeric nanocomposites, which hold great promise for many industrial applications. [ABSTRACT FROM AUTHOR]