Preparation and anti-wearing and anti-corrosion properties of 3D superhydrophobic coating based on poly-benzoxazine

Three-dimensional superhydrophobic coating was sprayed on carbon steel by adjusting the content and mass ratio of Al₂O₃-ZrO₂ fillers based on poly-benzoxazine (PBA) resin. Contact angle measuring, scanning electron microscope, friction and wear experiment and three-dimensional super depth of field microscope were used to study the structure-function relationship between the water contact angle on the surface of Al₂O₃-ZrO₂/PBA coatings and their microscopic surface morphologies. The effects of different Al₂O₃-ZrO₂ filler contents on the friction coefficient of coatings were compared. A mathematical model was established according to the relationship between the mass loss of 3D superhydrophobic coating and the friction distance under different loads, to predict the service life of the coating. The chemical stability of 3D superhydrophobic coating was investigated by employing different temperatures and different UV illumination time as the stimulation of external environment. The obtained results show that the contact angle of the coating reaches 154° when the mass ratio of Al₂O₃∶ZrO₂∶PBA is 1∶1∶2. The 3D superhydrophobic coating still exhibit superhydrophobic property (150°) even after suffering 180 cm friction distance under 5.66 kPa. The surface of the coating shows super hydrophobicity even at 300℃ after 1 h, indicating that the three-dimensional superhydrophobic coating behaves good chemical stability. The coating loses its superhydrophobic property after 30 min UV irradiation, and the superhydrophobic property can be quickly recovered after friction self-repairing. Besides, the anti-corrosion performance of the 3D superhydrophobic coating was also investigated, electrochemical tests show that the superhydrophobic coating has high impedance and behaves a good protection on carbon steel substrate.