Revealing and modeling of fire products in gas-phase for epoxy/black phosphorus-based nanocomposites

This work aims at revealing and optimizing the mechanism, to promote the design of phosphorus-based flame retardants (PFRs) for controlling the spread of fire risk caused by the continuous spread of polymers. Herein, we synthesized about 10 nm TiO₂ grown in situ on the surface of BP through a simple hydrothermal procedure to introduce it into epoxy (EP/BP-TiO₂). In the first place, EP/BP-TiO₂2.0 nanocomposite achieves a reduction of 58.96% and 50.35% in PHRR and THR, respectively. Secondly, the pyrolysis of BP from P_n to P₄, P₃ and P₂ is revealed. As a guide, P₄ is established as a characteristic product of the analytical model for evaluating the effects in the gas phase for BP-based hybrids. Finally, this work clarifies the enhancement path for BP-TiO₂ is optimized for the capturing of OH· and H· radicals by P₄(PO_x). Crucially, this study reveals and controls the mechanism of the BP-based hybrids at the molecular level, which is expected to provide a promising analytical model for broad market PFRs design to address the risks and challenges of casualties and ecology caused by composites fire.