Enhancement in the Mechanical Properties and Corrosion Resistance of Waterborne Polyurethane Coatings by Using Titanate‐Functionalized Graphene Oxide

ABSTRACT To enhance the mechanical strength and chemical resistance of waterborne polyurethane coatings, modified graphene oxide (HGO) was incorporated into cationic waterborne polyurethane (CWPU) via stepwise polymerization to yield HGO/CWPU composite coatings. By modifying GO with bis(triethanolamine) diisopropyl titanate, a triple‐action network of electrostatic attraction, hydrogen bonding, and covalent crosslinking was established within the CWPU matrix, enhancing the compatibility and interactions between GO and the polymer. Well‐dispersed HGO lamellae within the CWPU matrix created a physical barrier that markedly improved the mechanical strength, water resistance, and corrosion resistance of the coatings. The tensile strength of the HGO/CWPU‐0.7% composite coating reached 31.97 MPa, which was 4.54 times higher than that of pristine CWPU (7.05 MPa). This decreased the water absorption by 53.03%, while the corrosion current density dropped by three orders of magnitude, resulting in a corrosion prevention efficiency of 99.98%.