Fabrication of silane coating with improved protection performance using Mentha longifolia extract.

This work reports incorporation of Mentha longifolia in a silane coating to improve active corrosion protection. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were employed to characterize the chemical structure of extract. Electrochemical impedance spectroscopy (EIS) revealed that superlative corrosion resistance of silane primer was achieved at 200 ppm inhibitor concentration. DC polarization and open circuit potential (OCP) measurements confirmed the EIS results. The effect of inhibitor concentration on the crosslinking density was evaluated by FTIR and its subsequent effect on the coating wettability was assessed by water droplet contact angle method. The protective performance of the artificially defected bilayer coating system (silane + epoxy) assessed by EIS and surface analysis showed an improvement in the anticorrosion properties of silane formulated with 200 ppm extract due to the corrosion reaction restriction. Solution phase studies by electrochemical test and SEM indicated participation of a protective layer on the surface. [ABSTRACT FROM AUTHOR]