Tackling smoke toxicity and fire hazards of thermoplastic polyurethane by mechanochemical combination of Cu₂O nanoparticles and zirconium phosphate nanosheets

A major challenge is to adopt environmentally friendly means for the development of flame retardants of high efficiency in suppressing toxic smoke. An environmentally friendly method through mechanochemical treatment is reported herein to decorate zirconium phosphate nanosheets with Cu₂O nanoparticles (Cu₂O@ZrP) for suppressing the release of toxic products from thermoplastic polyurethane (TPU). Cu₂O@ZrP at 5 wt% provides TPU with a high tensile strength of 28.1 MPa and tensile toughness of 118.9 MJ·m − 3. It reduces the peak heat release rate by 46.2% and the peak smoke production rate by 40.2%. More importantly, Cu₂O@ZrP exhibits high efficiency in suppressing the volatile products, e.g., 27.1% reduction of CO. The mechanisms are explained from the synergy, physical barrier, and catalysis action of Cu₂O@ZrP. This work provides a green, facile approach for creating high-performance flame retardants to reduce the smoke toxicity and fire hazard of TPU.