Supramolecularly Functionalized Zirconium Phosphate Strategy for High‐Performance, Fire‐Retardant TPU in Automotive Applications

ABSTRACT Enhancing the fire safety of thermoplastic polyurethane (TPU), a polymer prized throughout the automotive industry, without degrading its mechanical properties is a critical industrial challenge. While two‐dimensional zirconium phosphate (ZrP) nanosheets offer promising flame‐retardant capabilities, their intrinsic aggregation tendency severely compromises their effectiveness in polymer matrices. Herein, ZrP nanosheets were functionalized via the surface self‐assembly of a bio‐based nitrogen‐phosphorus supramolecule derived from phytic acid (PA) and chitosan (CS), yielding the novel nanohybrid PC@ZrP. This nanohybrid's exceptional dispersion and interfacial compatibility within the TPU matrix enable a remarkable dual functionality. At 1 wt% loading, the TPU/PC@ZrP nanocomposite achieves a 42.6% enhancement in tensile strength alongside a 6.1% improvement in elongation at break. The material's fire safety is also substantially enhanced: a 3 wt% incorporation reduces the peak heat release rate and total heat release by 35.5% and 22.6%, respectively, while effectively suppressing smoke and toxic gas emissions. Mechanistic investigations revealed that this performance stems from synergistic flame‐retardant actions in both the condensed and gas phases. This work provides a robust, eco‐friendly strategy for creating multifunctional additives that bolster the fire safety and mechanical strength of polymer nanocomposites, paving the way for safer materials in demanding sectors like automotive manufacturing.