High performance polyurethane nanocomposite coatings based on 2D materials for improved anticorrosion and flame-retardant applications

Cobalt disulphide (CoS₂), 3-amino-5-ethoxy-1,2,4-triazole (AET), and graphene oxide, also known as GO, were added to polyurethane (PU) coatings to improve their anticorrosion and fire-retardant properties. To analyze the structural and morphological behaviours of the films of pure CoS₂, AET/CoS₂, GO/CoS₂, and GO/AET-CoS₂, SEM/EDX, TEM, TGA, XPS, and XRD techniques were used. The peak heat release rate (PHRR) and total heat release (THR) of polyurethane-graphene oxide/AET-CoS₂ were significantly lower than those of polyurethane, with differences of 64.7% and 52.8%, respectively, demonstrating better flame retardancy. The anticorrosive, hydrophobic, and flame-retardant characteristics of the PU-GO/AET-CoS₂ nanocomposite were confirmed using mechanical testing and electrochemical methods. Impedance studies confirmed that the corrosion protection performance of PU-GO/AET-CoS₂ in seawater was much greater (22,481 kΩ cm²) than that of the plain polymer (157 kΩ cm²). The PU-GO/AET-CoS₂ nanocomposite coated AA7039 aluminium alloy had the lowest aluminium ion dissipation as evidenced by SECM investigations. The PU-GO/AET-CoS₂ coating had superior hydrophobic properties (WCA: 164°). Therefore, PU-GO/AET-CoS₂ could be exploited as a potential material for coatings in industrial processes.