Corrosion behaviour of rubber-metal composites in sodium chloride solution and role of inhibitors added in the rubber or in the solution

The electrochemical behaviour of a metal-rubber composite is studied in NaCl-based solutions. The metallic reinforcement is brass-coated pearlitic steel. Electrochemical investigations were performed in 0.01 M NaCl and in a solution containing 0.01 M NaCl with species released from the rubber during immersion. These species were identified using gas chromatography coupled with mass spectrometry. The role as inhibitors of some species (released from the rubber or added in the solution) was evaluated by determining polarisation curves and electrochemical impedance diagrams. In the cathodic domain, no synergistic effect was noticed between 2-aminobenzothiazole (added in the solution) and benzothiazole (released from the rubber in the solution). It was found from EIS diagrams that inhibition is caused by specific adsorption at the specimen surface. In the anodic domain, it was proposed that there is a synergistic effect between 2-aminobenzothiazole and benzothiazole. (C) 2019 Elsevier Ltd. All rights reserved.