Sage extract as inhibitor of copper corrosion in 3% NaCl

Zbog sve veće brige stručne i naučne javnosti o zaštiti životne sredine došlo je do upotrebe ekološki prihvatljivih inhibitora za zaštitu metala od korozije. U ovom radu izvršeno je ispitivanje zaštite bakra obradom korozione sredine primenom različitih koncentracija ekstrakta žalfije 0.5g/dm3,1 g/dm3 i 1.5g/dm3, kao zelenog inhibitora, u rastvoru 3% NaCl. Merenja su izvedena gravimetrijskom metodom i elektrohemijskim metodama (Tafelovom metodom ekstrapolacije i spektroskopijom elektrohemijske impedanse). Najveće dostignute vrednosti zaštitnog faktora ekstrakta žalfije su 60,04% u rastvoru 3%NaCl + 1 g/dm3 i 53% u rastvoru 3%NaCl + 1,5 g/dm3 u vremenskom intervalu od 6 sati. Međutim, isti rastvori u vremenskom intervalu od 4 i 24 h deluju katalitički na proces korozije bakra, te se ekstrakt žalfije ne može preporučiti kao inhibitor korozije bakra u 3%NaCl. Rezultati dobijeni spektroskopijom elektrohemijske impedanse i rezultati dobijeni sa snimljenih Tafelovih polarizacionih dijagrama potvrđuju rezultate dobijene gravimetrijskom metodom, te se mogu preporučiti kao vrlo pouzdane metode za brza koroziona ispitivanja.Due to the increasing concern of experts and scientists on environmental protection use of environmentally friendly corrosion inhibitors for metal protection gains more interest. In this paper, research on copper protection by processing corrosive environment while applying different concentrations of sage extract of 0.5g/dm3,1 g/dm3 i 1.5g/dm3 as green inhibitor in 3% NaCl solution was performed. Measurements were carried out by gravimetric method and electrochemical methods (Tafel extrapolation method and electrochemical impedance spectroscopy). The greatest protective values of sage extract of 60,04% were reached in 3%NaCl + 1 g/dm3 solution and 53% 3%NaCl + 1,5 g/dm3 solution in 6 hours interval. However, the same solutions act catalytically on copper corrosion process during time interval from 4 to 24 hours, that is why sage extract can not be recommended as inhibitor of copper corrosion in 3%NaCl. The results obtained by electrochemical impedance spectroscopy and recorded Tafel polarization diagrams, confirm results attained by gravimetric method, thus can be recommended as very reliable methods for quick corrosion tests