In Situ Polymerization to Boron Nitride-Fluorinated Poly Methacrylate Composites as Thin but Robust Anti-Corrosion Coatings

High-performance anti-corrosion coatings featuring easy processability and thin thickness are highly desired in industry. Yet, solution process coating often faces a sedimentation problem with particles which are used as reinforcement in coatings. In this contribution, boron nitride (BN) was modified by an acrylate silane coupling agent (KH-570) to obtain acrylated BN flakes. Afterwards, the acrylated BN flakes were in situ copolymerized with 2-(perfluorohexyl)ethyl methacrylate to synthesize BN-fluorinated poly methacrylate (PFBP) composites. The as-obtained PFBP composites can form stable coating solutions, in which sedimentation of BN flakes seldom happens. The coating solution can easily form uniform coatings on various substrates with nanoscale thickness, confirmed by scanning electron microscope (SEM). The corrosion resistance of the samples coated PFBP coatings in 3.5 wt.% sodium chloride solution was evaluated by electrochemical impedance spectroscopy (EIS). It is indicated that the incorporation of BN flakes greatly reduce the corrosion rate. Adhesion measurements and abrasion resistance test indicate the PFBP coating performs good adhesion to substrate and robustness. Through the in situ polymerization, acrylated BN flakes are connected with the polymer chain, which inhibits the sedimentation of BN in the coating solution. Additionally, the BN flakes dispersed in the fluorinated polymer act as barriers, improving the corrosion resistance of the coated samples.