Constructing coral-like PDA layer on glass fiber to enhance the erosion resistance of epoxy coating

[Display omitted] •Coral-like PDA layer was constructed on the surface of glass fiber by regulating the reaction concentration of dopamine.•CT confirmed that glass fiber with coral-like PDA layer had good dispersion in epoxy resin.•(PDA1.5@GF)/EP coating displayed the best mechanical properties, anti-wear and erosion resistance performance.•The coral-like PDA layer could form mechanical meshing between GF and EP, thus significantly enhancing the erosion resistance of GF/EP coating. Glass fiber (GF) reinforced epoxy resin composite materials are widely used in wind power, automobiles, and ships, etc. The failure of glass fiber reinforced epoxy resin composites (GF/EP) is mainly attributed to the smooth surface and chemical inertness of GF. Dopamine, extracted from the adhesive protein secreted by mussels, exhibits excellent adhesion performance especially in wet environments. Thence, we constructed a coral-like layer of dopamine nanoparticles on the surface of glass fiber (PDA@GF) by self-surface polymerization deposition, which could simultaneously improve the chemical activity and roughness of the fiber surface, and form mechanical meshing and chemical bonding with the epoxy resin, thereby enhancing the interfacial adhesion strength between GF and EP. PDA layer with different surface morphologies were constructed on the GF surface by finely adjusting the reaction parameters, and the influences of surface morphologies on the mechanical performance of GF/EP coatings were explored. Based on the results obtained from tensile test, friction test, and erosion test, it was evident that the PDA@GF/EP composite material exhibited superior mechanical properties when the PDA layer exhibited a coral-like morphology, in comparison to the other two kinds of surface morphologies. Meanwhile, the dispersion of the fiber within the epoxy resin was examined using X-ray computed tomography (X-ray CT). On this basis, we investigated the anti-wear performance and erosion resistance of composite coatings with different fiber contents, furthermore, we revealed the anti-wear and anti-erosion mechanism.