Alkaloid and Non-Alkaloid Ethanolic Extracts from Seeds of Garcinia Kola as Green Corrosion Inhibitors of Mild Steel in H₂SO₄ Solution

摘要

The inhibitive effects of the extracts of Garcinia kola seeds: ethanolic (EEGK), alkaloid ethanolic(AEGK) and non alkaloid ethanolic (NEGK) on the corrosion of mild steel in sulphuric acid mediumwas investigated using the hydrogen evolution (via gasometric assembly) and the weight loss methodsat 307- 373 K. The extracts were found to inhibit mild steel corrosion to different extents in thefollowing order AEGK > EEGK > NEGK. The inhibition efficiency increased with increase in theconcentration of the inhibitors and decrease in temperature. A phenomenon of physical adsorption isproposed for the inhibition from the trend of inhibition efficiency with temperature, Ea and adsvalues, and the process followed the Langmuir adsorption isotherm.