Anticorrosion performance of polyvinyl butyral composite coatings improved by polyaniline-multiwalled carbon nanotubes/poly (methylhydrosiloxane)

Abstract 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.