Phosphorous-Nitrogen flame retardants engineering MXene towards highly fire safe thermoplastic polyurethane

Developing high-performance polymeric materials with highly effective flame retardancy and the generation of ultra-low toxic fumes in a fire remains an intractable challenge. In this work, a novel titanium carbide-polyphenyl phosphate ester amide hybrid (Ti 3 C 2 T x -PPPA) was synthesized via the esterification and hydrogen bonding induced assembly for fabrication of thermoplastic polyurethane (TPU) nanocomposites. The Ti 3 C 2 T x -PPPA displayed strong interface interaction with TPU matrix. The cone calorimetry results indicated that the total heat release, total smoke release and total carbon monoxide yield of the TPU nanocomposite with 1.0 wt% Ti 3 C 2 T x -PPPA were dramatically decreased by 32.6%, 54.4% and 36.8%, respectively, compared to those of pristine TPU. Besides, TPU/Ti 3 C 2 T x -PPPA-1.0 showed the highest Flame Retardancy Index (1.76) among all the specimens. The improved fire safety of TPU was ascribed to the catalytic charring, the chemical transformation and the barrier effect of the Ti 3 C 2 T x nanosheets and PPPA trapping free radicals. This work provides a promising strategy for significantly improving the fire-resistance of TPU and further widening its industrial application. • Ti 3 C 2 T x -PPPA was prepared by hydrogen bonding induced assembly of Ti 3 C 2 T x and PPPA. • Ti 3 C 2 T x -PPPA hybrid showed strong interface interaction with TPU matrix. • TPU/Ti 3 C 2 T x -PPPA nanocomposites exhibited markedly reduced total smoke release and total CO yield. • Decreases are due to multiple charring, barrier and quenching effect of Ti 3 C 2 T x -PPPA hybrid.