Corrosion protection of hydrophobic bisphenol A-based polybenzoxazine coatings on mild steel

Abstract

Hydrophobic bisphenol A-based polybenzoxazine (PBA-a) coatings were prepared on mild steel (MS) through a simple dip coating and thermal curing method. The thermal curing process of PBA-a coating was studied by Fourier transform infrared spectrometer (FTIR) and differential scanning calorimeter (DSC). The film-forming property and the wettability of PBA-a coatings were characterized by the microscopy and the contact angle measurement, respectively. The effects of benzoxazine monomer concentration and curing temperature on corrosion resistance of PBA-a coatings on MS were investigated by the electrochemical measurements. The results revealed that the corrosion resistance properties of PBA-a coatings improved with the increasing concentration of BA-a monomer. For the samples with the BA-a concentration of 500 g L⁻¹, the protection efficiency values of PBA-a coatings were more than 99.0% when the curing temperature increased from 150 °C to 210 °C.