Abstract

K. Anbarasi

DOI : http://dx.doi.org/10.13005/ojc/320443

The  influence  of  the   acid  extract  of  peel of  Cucurbita maxima (PCM) on  the corrosion   of  mild steel  in  1N H₂SO₄ was investigated by weight loss, polarization and impedance methods and SEM analysis. The inhibition efficiency increases with extract concentration and immersion period. Weight loss and corrosion rates of mild steel decreased as the concentration of inhibitor increased.  The results showed that PCM was potential corrosion inhibitor and maximum inhibition efficiency (IE %) obtained was   98% for 3%PCM at 1h. Impedance measurement results an increase in charge transfer resistance (R_ct), which also confirms the corrosion inhibitive nature of the plant extract. Potentiodynamic study showed that PCM acts as a mixed type of inhibitor, which controls both the anodic and cathodic reactions. Scanning electron microscopic studies provided the evidence of improved surface condition for the corrosion protection, due to the adsorption.

Adsorption; Polarization; Impedance; Corrosion rate; Inhibition efficiency

[ View HTML Full Text]