PTFE-based flame retardant coatings optimized by melamine polyphosphate/aluminum diethyl hypophosphite/anhydrous transparent powder through orthogonal experiment

Hence, a novel hydrophobic intumescent flame-retardant coating is prepared using melamine polyphosphate (MPP), aluminum diethylphosphinate (ADP), and anhydrous transparent powder (ATP) as intumescent flame retardants (IFR), doped with polytetrafluoroethylene emulsion (PTFE) for flame-retarding plywood. The IFR/PTFE coatings are prepared using the sol-gel method. Firstly, the cone results demonstrate a significant enhancement in the flame retardancy of IFR/PTFE coatings. The Total Heat Release (THR) is reduced from 35.71 MJ·m−2 to 16.07 MJ·m2, while the Flame Retardancy Index (FRI) increases from 1 to 32.52. Moreover, according to the 3D Jander model (n = 3), the activation energy (Eα) for the coating rises from 209.52 to 253.50 kJ·mol−1 in the range of 327 °C to 430 °C. The coating achieves a maximum water contact angle of 113°. Notably, the optimal formulation of IFR is explored through orthogonal experiments, and the further optimized formulation (MPP: 21.16 wt%, ADP: 5.05 wt%, ATP: 10.17 wt%) is predicted using regression analysis model based on the Design of Experiments (DOE) method. Generally, it explores a strategy for preparing efficient IFR/PTFE hydrophobic coatings with promising prospects.