Trans-1,4-polyisoprene (TPI)) Extracted from Eucommia bark as Natural Corrosion Inhibitor for Carbon Steel in the Simulated Concrete Pore Solution

Abstract

The aim of the work was to extract Gutta-percha (trans-1,4-polyisoprene (TPI)) from Eucommia bark and leaves as a natural corrosion inhibitor to inhibit Q235 carbon steel corrosion in a simulated concrete pore solution that contains 3.5wt% NaCl. The results of a SEM study of the surface morphology of steels with and without inhibitors revealed that inhibitor molecules formed a protective layer on the carbon steel surface, which retarded the attack of the Cl- species and significantly inhibited carbon steel corrosion in a simulated concrete pore solution. EIS and polarization measurements were applied to electrochemical corrosion studies of carbon steel, and results indicated a good agreement between the EIS and polarization studies, which revealed how to enhance the corrosion resistance of Q235 carbon steel with the addition of the TPI as inhibitor in corrosive media. Results showed that the maximum values of corrosion inhibition efficiency were obtained at an average of 85.48% for Q235 carbon steel in the simulated concrete pore solution containing 2.0 g/L of TPI.