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Polyaniline-carboxylic multiwalled carbon nanotubes (PANI-CMWCNTs) nanocomposites was prepared by a facile in-situ polymerization. PANI-CMWCNTs nanocomposites were incorporated into polyvinyl butyral (PVB) to prepare a protective coating on AA2024 aluminum substrates using a spin coating method. Besides, Poly (methylhydrosiloxane) (PMHS) was added to increase the crosslinking of the coating and form a hydrophobic surface. Scanning electron microscope, transmission electron microscope, UV–visible spectroscopy and Fourier transform infrared spectrum were used to characterize the morphologies and structures of different composites. The corrosion protection properties were investigated by electrochemical impedance spectroscopy and Tafel polarization in 3.5 wt% NaCl solution. Results showed that the PVB/PANI-CMWCNTs/PMHS composite coating exhibited remarkably enhanced anticorrosion properties, the corrosion current density (Icorr) of the coating decreased to 0.039 μA•cm−2, and the impedance value (|Z|0.01Hz) of the coating significantly improved compared with bare aluminum and exceeded 107 Ω•cm2, and the long-term corrosion resistance of the coating could last for over 60 days. The anticorrosive efficiency of PVB coating was promoted and an idea for the preparation of environmentally friendly coatings was proposed.

A novel environment-friendly composite coating (P/P'-Ch-P/P') was prepared by layer-by-layer assembly of polyvinyl butyral (PVB), polymethylhydrosiloxane (PMHS) and chitosan (Ch) on AA 2024 substrate to improve the corrosion resistance of AA 2024 sample. The properties of the coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and laser confocal microscope. The results showed that the addition of PMHS increased the hydrophobicity of composite coating；as the intermediate layer, Ch also crosslinked other components while forming the film. At the same time, the corrosion resistance of the coating in 3.5 wt.% NaCl solution was characterized by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Compared with the bare aluminum substrates, the impedance modulus of the composite coating was increased by 3 orders of magnitude; the corrosion current density (Icorr) of the composite coating was reduced by 5 orders of magnitude. The results of long-term immersion test showed that the composite coating still had good anticorrosion ability after 60 days. This study provides a simple and environment-friendly method for corrosion protection of aluminum alloy in marine environment.

In this paper, polyaniline (PANI) was used as anticorrosive filler and waterborne epoxy resin (EP) as film-forming material to prepare anticorrosive coatings on 304 stainless steel. Poly(methylhydrosiloxane) (PMHS) with low surface energy and divinylbenzene (DVB) as crosslinking agent were used to modify the coatings. FT-IR proved the successful preparation of Polyaniline and composite coatings. The micro-morphology and surface state of the coatings were studied by scanning electron microscopy (SEM) and contact angle measuring instrument (CA). Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were used to evaluate the corrosion resistance of different coatings in 3.5 wt% NaCl solution. The surface of the composite coatings after surface modification became hydrophobic (CA = 98°), compact and uniform, and the anti-corrosion performance significantly improved. Compared with bare sheets, the |Z|0.01Hz of the composite coatings had been increased by more than three orders of magnitude, and the corrosion current density had been reduced by five orders of magnitude. Long-term immersion test showed that the coating was able to provide effective protection to the substrate for about 140 days.