Expired drugs as vapor-phase corrosion inhibitors of copper in simulated marine atmospheric environment

Urea, paracetamol and glutamine (based on the expired drugs) were selected as vapor-phase corrosion inhibitors (VCIs) to study their corrosion protection effect on red copper in simulated marine atmospheric environment by using weight loss, electrochemical measurement techniques (specially designed electrochemical testing device for simulating marine atmospheric environments) and surface morphology characterization analysis (SEM/EDS, XRD, RAMAN, XPS). Weight loss results show that the three corrosion inhibitors have good corrosion inhibition effect on red copper, and the corrosion inhibition efficiency in the order of glutamine (83.62%)>urea (68.46%)>paracetamol (61.47%). Surface morphology characterization analysis provides evidence of adsorption of corrosion inhibitors molecules on the red copper surface, thus forming a protective film that blocked the red copper surface from the aggressive chloride ion attack.