Synergistic Incorporation of Boron Nitride Nanosheets and Fluoropolymers to Amplify Anti-Corrosion Attributes of Waterborne Epoxy Resin

The corrosion of metal substrates is closely associated with the permeability of the corrosive medium in which they are immersed. To enhance the protection of metal materials and improve anti-corrosion performance from an epoxy resin perspective, the diffusion path complexity can be increased and porosity reduced within the epoxy resin coating to effectively block the invasion of corrosive media. Simultaneously, reducing the affinity between the corrosive media and the epoxy resin coating makes it difficult for corrosive substances to adhere. Based on this principle, this study introduces two-dimensional boron nitride nanosheets (BNNS) and fluoropolymers-modified one-dimensional nano-silica (SiO2) and organic tannic acid as fillers to jointly enhance the protective effect of waterborne epoxy-resin-based composites. Experimental results demonstrate that when the BNNS content is 0.5 wt.%, the 0.5-BNNS/WEP composite coating exhibits superior anti-corrosion performance, achieving an electrochemical impedance of 2.90 × 107 Ω∙cm2. Moreover, when BNNS is compounded with fluorinated SiO2 or fluorinated tannic acid as fillers and incorporated into waterborne epoxy resin, the resulting composite coatings maintain excellent long-term anti-corrosion performance even after 20 days of salt spray testing.