Improvements of adhesion strength of water-based epoxy resin on carbon fiber reinforced polymer (CFRP) composites via building surface roughness using modified silica particles

In this work, aiming to enhance the adhesion strength of water-based epoxy coating on carbon fiber reinforced polymer (CFRP) composites, micron silica particles modified by γ-amino propyltriethoxysilane (γ-APS) with the sol-gel method were used to build roughness surface on CFRP. The morphology, roughness, chemical composition, wetting behavior of the surface were characterized and their effects on the coating’s adhesion strength through Pull-off adhesion test were analyzed. It was demonstrated that the introduction of modified silica particles improves the adhesive strength of epoxy coating on CFRP by approximately 120%. Compared to traditional sanding treatments of CFRP composites, this work provides a convenient and eco-friendly approach to reach the adhesion strength requirement for the water-based epoxy coating without composites mechanical damage and dust pollution.