Bioactive cross-scale interfacial functionalization: improving the seawater corrosion resistance of basalt fiber composite insulation materials

Abstract

To improve the poor interfacial bonding between basalt fiber-reinforced composite materials in marine environments and promote their application in large-scale electrical equipment, this paper uses chitosan and polydopamine nanoparticles to create a cross-scale structure on the basalt fiber surface. It also provides a detailed analysis of the infiltration properties of basalt fiber after coating treatment and conducts experiments on seawater corrosion of the composite material (DCS-BFRP). These experiments demonstrate the improved corrosion resistance of the composite. The bioactive coatings were analysed by testing the electrical, mechanical, and physical properties of DCS-BFRP. The results show that, compared to commercial basalt fiber, the coating treatment effectively improves the hydrophilicity and tensile strength, increasing the surface energy by 26.10%, the permeability by 63.52%, and the TFBT strength by 34.82%, while promoting a more prominent interfacial bonding effect. After seawater corrosion, the breakdown strength retention rate of DCS-BFRP reached 72.57%, the dielectric loss factor increased to 1.25%, the bending strength retention rate reached 75.59%, the self-corrosion current density decreased by 24.54%, and it had stronger hydrolysis resistance and higher glass transition temperature. The cross-scale composite bioactive coating combines the advantages of both “rigid” and “soft” transition layers. It resists the erosion of corrosive media on the fibers, improves the seawater corrosion resistance of DCS-BFRP, and provides a reference for the research and development of environmentally friendly special infiltration agents for basalt fibers.