Preparation and anticorrosion performance of nano polyaniline/polyurethane interpenetrating network composite coating

Abstract Polyaniline−dodecylbenzene sulfonic acid (PANI‐DBSA) particles were synthesized through in situ lotion polymerization of aniline and DBSA as raw materials, followed by combining with epoxy resin (E‐44) and castor oil (CO) to prepare a PANI mixture (PANI‐DBSA/CO) which was used as a nanofiller to create a nano polyaniline/polyurethane (PANI‐PU) interpenetrating polymer network (IPN) coating. SEM, XRD and Fourier transform infrared spectroscopy were used to characterize the PANI‐DBSA and PANI‐PU IPN composite coatings that were produced. The coatings’ physical and mechanical characteristics were investigated, as well as the system's corrosion behaviour in 3.5 wt% NaCl solution, utilizing electrochemical impedance spectroscopy and electrokinetic polarization. Acid, alkali and saltwater immersion investigations were used to further evaluate the coatings’ medium resistance. The results show that when PANI‐DBSA is added at 1 wt%, the contact angle reaches 102.6°, the adhesion reaches S1 grade after 720 h immersion, the tensile strength is 16.22 MPa and the elongation reaches 208%. The impedance value of the composite coating grew by 569 times with the addition of 1 wt% PANI, and the resistance duration to 10 wt% H 2 SO 4 , 10 wt% NaOH and 3.5 wt% NaCl reached more than 90 days. The addition of PANI to IPN coatings can increase corrosion resistance and extend their application range. © 2023 Society of Industrial Chemistry.