Exudate Gum from Acacia Trees as Green Corrosion Inhibitor for Mild Steel in Acidic Media

摘要

The inhibition effect of exudate gum from Acacia trees (Gum Acacia, GA) on the corrosion of mildsteel in acidic media was studied by weight loss, hydrogen evolution, and electrochemical polarizationmethods; also, surface morphology was analyzed by Fourier transform infrared spectroscopy (FTIR),scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. Theresults of weight loss, hydrogen evolution, and electrochemical polarization methods indicated thatinhibitor efficiency (I%) increased with increasing inhibitor concentration. The inhibitor efficiency(I%) in hydrochloric acid is much more than those in sulfuric acid due to the synergistic effect. Thepercentage inhibition efficiency (I%) of steel corrosion with GA is highly increased in the presence ofan external magnetic field. Results of weight loss method are highly consistent with those obtained byhydrogen evolution method, and both indicate that inhibitor efficiency increases with increasinginhibitor concentration and the presence of external magnetic field. Electrochemical polarizationstudies showed that Gum Acacia acts as mixed type inhibitors. The results reveal that Gum Acaciaprovided a very good protection to mild steel against corrosion in acidic media. FTIR, SEM and XPSconfirmed the existence of an absorbed protective film on the mild steel surface.