Functionalizing MXene with hypophosphite for highly fire safe thermoplastic polyurethane composites

Owing to the superior abrasive resistance, processability and self-lubricating performances, thermoplastic polyurethane (TPU) has attracted numerous attention in the areas of automotive steering wheels, electronic industry and national defense, etc. However, the industrial applications of TPU are imped due to its highly intrinsic flammability and the release of a lot of smoke and hot during combustion. To address this hurdle, herein, a hybridized flame retardant (ATi3C2Tx) was synthesized by the hydrogen-bonding interaction between titanium carbide (Ti3C2Tx) and aluminum hypophosphite (AP). The results indicated that incorporated 9.5A0.5Ti3C2Tx decreased the peak of heat release rate, total heat release, total smoke release and total CO yield of TPU by 69.2%, 50.9%, 63.7% and 20.6%, respectively. Besides, the TPU/9.5A0.5Ti3C2Tx composite passed the UL-94V-0 rating test and obtained the highest LOI (29.9%) among all the specimens. The improved fire resistance of TPU composites was ascribed to the multiple effects of the ATi3C2Tx hybrid.