A new corrosion protection approach for aeronautical applications combining a Phenol-paraPhenyleneDiAmine benzoxazine resin applied on sulfo-tartaric anodized aluminum

[Display omitted] •AA1050 and AA2024-T3 substrates have been anodized in sulfo-tartaric electrolyte.•P-pPDA benzoxazine coatings have been applied on anodized aluminum substrates.•Thermal curing cycles have been performed in order to cross-link the applied resin.•High and durable barrier properties are achieved with such systems.•A favorable interface is observed between anodic and organic layers. In this paper, the feasibility to apply a laboratory synthesized Phenol-paraPhenyleneDiAmine (P-pPDA) benzoxazine by spin coating on anodized aluminum substrates followed by thermal curing, has been investigated. Prior to coating, sulfo-tartaric anodizing has been carried out aiming at growing porous oxide layers either on 1050 or 2024-T3 aluminum substrates. Optimization of the performance of the benzoxazine coatings to protect the aluminum substrates was achieved by working out conditions preventing delamination of the coatings – as observed for non anodized coated substrates – and reducing its curing temperature to a level compatible with the requirements of the aerospace industry. Compared to bare substrates coated with P-pPDA, it is shown that highly capacitive and durable barrier properties can be obtained for the same kind of coatings when applied on the anodized substrates. Moreover, in order to respect the thermal sensitivity of aeronautical aluminum substrates, such as 2024-T3, the curing temperature can be limited to 140°C only if the substrates are previously anodized in a sulfo-tartaric acid bath.