Natural extracts The natural extrac

Natural extracts The natural extracts were obtained from a natural product company, Cairo, Egypt. The main components in the three natural extracts are given in Table 1. Results and discussion Galvanostatic polarization Figure 1 clarifies the impact of different concentrations of the cassia bark extract on the galvanostatic anodic and cathodic polarization curves of C-steel electrode in 0.5 M H2SO4 solutions. Analogous curves were also obtained for the parsley extract and curcumin extract, but it is not shown here. Some corrosion parameters were anodic (ba) and cathodic (bc) Tafel constants, cor- rosion potential (Ecorr), corrosion current density (icorr.), surface coverage (θ) and the percentage inhibition effi- ciency (%IE). The corrosion parameters were calculated from the intercept of the anodic and cathodic Tafel lines and are present in Table 2. 200 Table 1. The IUPAC name, molecular weight and molecular formula of the major component found in the three natural extracts used as green corrosion inhibitors.