Engineering heat-resistant and intrinsic flame retardant poly(aryl ether) coatings containing triazine structure for marine corrosion protection

High-temperature oxidation and salt spray corrosion synergistically degrade marine propulsion components, demanding protective coatings that integrate thermal stability, interfacial adhesion, and electrochemical barrier properties. To address this, novel series of poly(biphenyl ether triazine nitrile)s (PBTNs) were prepared by incorporating rigid phenyl- s -triazine moieties into polyarylether backbones. The materials exhibit exceptional thermal resilience with high decomposition thresholds exceeding 550 °C under nitrogen atmosphere and glass transition temperatures above 215 °C, coupled with intrinsic self-extinguishing behavior validated by UL-94 V-0 certification. As coatings, PBTNs demonstrate comprehensive mechanical robustness including superior surface hardness, excellent impact resistance and strong substrate adhesion. Crucially, electrochemical verification confirms outstanding long-term corrosion protection in marine conditions, where the optimal sample maintains protective integrity through 1200 h of continuous salt spray testing without visible rust formation. Selected formulations further resist concentrated alkaline solutions (35 wt% NaOH) and acidic media (10 wt% H 3 PO 4 ) for extended 30 d exposures. This molecular design establishes a new paradigm for high-temperature protective coatings in marine engineering applications, significantly enhancing operational durability while reducing lifecycle maintenance burdens across maritime infrastructure systems.