Abstract
Isolated from black pepper (BP) extract, piperanine was tested as corrosion inhibitor of C38 steel corrosion in 1 M HCl solution. Piperanine was identified by NMR techniques. The corrosion tests were conducted by weight loss method at various temperatures varying from 298 to 353 K. Results obtained from weight loss measurements indicate that the natural compounds tested exhibit higher efficiency exceeding 97.5% at 10-3 M piperanine. Piperanine adsorbs on the steel surface according Langmuir isotherm. Adsorption enthalpy were determined and discussed. Effect of temperature was also investigated and activation parameters were evaluated.