Effect of phosphorus/nitrogen/carbon component ratio in aqueous flame retardant on the fire prevention of wood substrate

Herein, various of aqueous halogen‐free flame retardants (FRs) were fabricated by controlling the weight ratio of phosphorus/nitrogen/carbon compounds. The prepared FRs showed good dispersion level at ambient conditions and easily adhering feature on the wood substrate. Owing to the synergistic flame‐retardant effect of phosphorus/nitrogen/carbon compounds on wood, the FR1 coated wood (W‐FR1) could form non‐pores, compact, and continuous phospho‐carbonaceous layer under fire. Meanwhile, W‐FR1 exhibited a higher LOI (59.5%) and UL‐94 rating (V‐0). Moreover, the ignition time of W‐FR1 was significantly delayed from 35 to 570 s. Additionally, W‐FR1 showed 31.6% and 47.1% reductions in THR and TSP, respectively, 99.3% increment in char residue, as compared to the untreated wood. The present research offers a promising aqueous flame retardant for potential forest fire prevention.