Novel sustainable corrosion inhibitors for enhancing carbon steel corrosion resistance based on clay and lignin biopolymer extracted from raw Alfa fibers.

Within the scoop of environmental sustainability, the elaboration of efficient inhibitors using biomaterials was investigated. Beginning with careful extraction of lignin from raw Alfa fibers. Following this, the study examined the synthesis and characterization of a new generation of corrosion inhibitors based on clays and lignin biopolymer. A comprehensive characterization of powder samples sepiolite-lignin (SP-L) and bentonite-lignin (BN-L) was executed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) analysis and scanning electron microscopy (SEM) images. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were conducted on carbon steel immersed in 3%NaCl solution containing SP-L and BN-L composites, showing an interesting inhibition efficiency of 92.0% and 90.2%, respectively. The surface characterization of carbon steel, subsequent to immersion in 3%NaCl solution without and with SP-L or BN-L was conducted using XRD, FT-IR and SEM coupled with energy-dispersive X-ray spectroscopy analysis. Interestingly, the results of the blank sample revealed a deposition of corrosion products; mainly FeO(OH), Fe3O4 and iron carbonate (FeCO3), while SP-L and BN-L samples revealed an organic layer adsorbed onto the CS surface acting as a protective barrier. [ABSTRACT FROM AUTHOR]