Zeolitic imidazolate frameworks dispersed in waterborne epoxy resin to improve the anticorrosion performance of the coatings

Reasonable design of inorganic nano-base materials to promote the anticorrosion performance of waterborne epoxy resin (EP) coating remains a great challenge. Herein, we describe the preparation method and anticorrosion properties of zeolitic imidazolate framework (ZIF-67) composite coatings. ZIF-67 could be used as both anticorrosion filler and pigment for the coatings. The addition of ZIF-67 improved the impermeability of the coating, thus slowing down the chemical reaction on the surface of the substrate. The long-term corrosion-resistant performance of composite coatings (ZIF-67@EP) in 3.5% NaCl solution was evaluated comparatively. Before immersion, the low-frequency impedance of 1% ZIF-67@EP coating was 2.5 times of 0% ZIF-67@EP coating, and after 14 days of immersion, the low-frequency impedance of 1% ZIF-67@EP coating was still 1.8 times of 0% ZIF-67@EP coating. The corrosion rate of 1% ZIF-67@EP coating was decreased by 177 times.

Hydrophobicity and corrosion resistance of waterborne fluorinated acrylate/silica nanocomposite coatings

This study aims to improve the hydrophobic properties and corrosion resistance of fluorinated acrylate coatings. The surface of nano-SiO2 was modified by the silicone coupling reagent (KH-570), and the reactive functional groups were introduced to modify fluorinated acrylates. The functionalized SiO2-modified waterborne fluorinated acrylate emulsion was prepared by free polymerization with dual initiators. The structure of the polymer was analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectro-meter (1H-NMR), X-ray photoelectron spectroscopy (XPS) and Waters gel chromatography (GPC). The properties of the films and coatings were analyzed by contact angle, atomic force microscopy, scanning electron microscopy, and electrochemical analysis. The results showed that the contact angle reached 120° when the SiO2 content was 3%, the electrochemical impedance value reached 1.49 × 107 Ω·cm2, and the pencil hardness was 3H.