Sílica decorada com uma base de schiff como revestimento anticorrosivo para liga de alumínio 2024 – T3.

Abstract

A new Schiff base orthosilicate were synthesized and their inhibitive properties against corrosion when deposited on the 2024-T3 aluminum alloy in 0.05 molL-1 NaCl were investigated by electrochemical techniques as electrochemical impedance spectroscopy and potentiodynamic polarization beyond of scanning electron microscopy. Preliminary results showed that, the new Schiff base orthosilicate exhibits inhibitor properties against corrosion under open circuit potential.The proper characterizations of each step of the synthesis of the Schiff base and the new Schiff base orthosilicate were performed by infrared spectroscopy, C13 NMR, H1 NMR and Si29 NMR.The silica used in the present work was efficiently extracted from the rice husk and its decoration with the Schiff base showed excellent anticorrosive properties when deposited on 2024-T3 aluminum alloys.The corrosion protection efficiency in both the open circuit and polarization potential increased as the number of immersion steps of the alloy in the solution containing 3000 ppm of the Schiff base orthosilicate synthesized. An anticorrosive mechanism based on the adsorption of the silanol groups and the formation of complexes between the Schiff base orthosilicate and the Cu + 2 cations that are products of the corrosion mechanism of these alloys was proposed in the present work.