Facile construction of hydrophobically modified epoxy coatings with excellent anti-corrosion, abrasion resistance and self-cleaning performances

Superhydrophobic coatings show great application prospect in various fields such as corrosion protection, antiicing, waterproof and oil-water separation, due to their unique properties. However, the poor mechanical stability and the preparation complexity severely limit their practical application. In this study, superhydrophobic epoxy coatings with excellent mechanical stability were facilely constructed based on fluoridation modification of amine curing agent and TiO2 nanoparticles. Epoxy curing agent, diethyltriamine, was fluorinated by the reaction with heptafluorobutyric acid to obtain the required low surface energy. Meanwhile, fluorinated TiO2 nanoparticles were prepared through the reaction with 1 H,1 H,2 H,2H-perfluorooctanetriethoxysilane and further used for generating the roughness. The properties of the coatings were adjusted by the addition amount ratio of TiO2 nanoparticles to epoxy resin. The performance tests of water wetting, abrasion resistance, and corrosion resistance of the coatings were carried out. The results show that the hydrophobicity of epoxy coating is greatly improved after fluoridation modification of amine curing agent, and the greater the amount ratio fluorinated TiO2 nanoparticles to epoxy resin, the higher hydrophobicity of the modified coating. The modified coating prepared under optimal conditions displays excellent abrasion resistance, self-cleaning and anticorrosion performances. The electrochemical impedance spectroscopy tests in 3.5 wt% NaCl solution reveal that the hydrophobically modified epoxy coating has the largest charge transfer resistance, which is 8 orders of magnitude larger than that of uncoated Q235 steel. This work provides a simple method for preparation of superhydrophobic epoxy coatings with excellent mechanical stability, and will enlighten researchers to develop more superhydrophobic coatings and their applications.