A superior organic anticorrosion coating based on p-toluenesulfonate-doped polypyrrole to boost oxide film formation on aluminum substrates

Purpose Developing efficient functional anti-corrosion coatings has recently attracted widespread attention. This study aims to formulate a high-performance anti-corrosion coating by incorporating p-toluenesulfonate (PTSA)-doped polypyrrole (PPy) into the epoxy resin. The PPy-PTSA promotes the formation of a protective oxide film at the coating-aluminum alloy interface, thereby significantly enhancing the corrosion resistance. Design/methodology/approach PPy-PTSA powder was synthesized via the chemical oxidation method, and composite coatings with varying PPy-PTSA loadings (4, 6 and 8 Wt.%) were prepared. The passivation and anticorrosion performance of these coatings were assessed by electrochemical tests. Findings The PPy-PTSA/EC-6% composite exhibited superior passivation performance, forming a dense, thick oxide film on the aluminum alloy substrate. This coating thus demonstrated outstanding corrosion resistance, acting as an effective barrier against corrosive electrolytes for durable protection. Originality/value This study presents a novel strategy for corrosion protection by synergistically integrating the active passivation of a PPy-PTSA-induced oxide film with physical barrier effects of organic coatings. This work provides valuable insights and paves the way for developing sustainable coatings, particularly suited for demanding marine applications on aluminum alloys.