A study on anticorrosive property of phenolic components from Pachysandra terminalis against low carbon steel corrosion in acidic medium

Abstract

Purpose The study aims to find new anticorrosive components from a plant source, namely, Pachysandra terminalis Sieb. et Zucc. (P. terminalis), a traditional medicinal shrub predominantly used by Tujia people. Design/methodology/approach Because phenolic components from plants are known for its numerous values in several fields, the corrosion inhibitive ability of P. terminalis extract was analyzed by electrochemical studies (polarization, electrochemical impedance spectroscopy) and surface examination (by scanning electron microscopy [SEM], energy-dispersive X-ray spectroscopy [EDX] and atomic force microscopy [AFM]). Findings The examination of total phenolic content (TPC), total flavonoids content (TFC) and individual phenols (UHPLC) showed the presence of 85.21 mg/g (TPC), 25.38 mg/g (TFC), protocatechuic acid (62.10 µg/g), gentisic acid (60.21µg/g), rutin (50.12 µg/g), kaempferol (46.58 µg/g) and p-Coumaric acid (42.35µg/g) . The polarization study shows that the maximum shift is (16 mV), imposing a mixed mode of inhibition, dominantly anodic. The surface morphology studies by SEM, EDX and AFM confirmed the adsorption of phytochemical components on the low carbon steel surface blocking the active sites. Originality/value The study unveils the inhibitive nature of P. terminalis, preventing aggressive attack by 0.5 M HCl on low carbon steel. This also exhibits few phenols present in methanolic leaf extract which may be the role player of corrosion inhibition.

Anti-corrosive potential ofCyperus rotundusas a viable corrosion inhibitor for mild steel in sulphuric acid

“…AFM is an efficient tool for depicting microstructure (Kumar et al , 2017; Chitra et al , 2019). Two-dimensional (2D) images of mild steel in 0.5M H 2 SO 4 in the absence and presence of the inhibitor are depicted in Figure 4.…”

Evaluation of Antioxidant and Anticorrosive Activities of Ceriops tagal Plant Extract

“…AFM is a potent tool for determining the surface topography of the polished mild steel exposed to (1 M) HCl along with and without green inhibitor. As shown in Figure 7, the two-dimensional (2D) surface morphology of mild steel treated with 1 M HCl reveals a severe crack in the surface (Figure 7a) and 1 M HCl with 600 ppm inhibitor significantly diminished the surface crack (Figure 7b) [61][62][63]. The average roughness (251 nm) of the mild steel before the exposure to acidic solution were noticed and, in the presence of the optimal concentration of C. tagal plant extract, the reduced average roughness was determined (65 nm), which confirmed the anticorrosion efficiency of the adsorbed inhibitor molecules produced by the protective film [64][65][66].…”

Use of Trochodendron Aralioides Extract as Green Corrosion Inhibitor for Mild Steel in 1M HCl Solutions

“…Figure 9b shows the MS specimen's surface morphology in the presence of the inhibitor where a smooth surface was detected. The SEM image indicates that IE was increased by adsorption of the inhibitor on the metal's surface [61][62][63][64].…”

“…Figure 9b shows the MS specimen's surface morphology in the presence of the inhibitor where a smooth surface was detected. The SEM image indicates that IE was increased by adsorption of the inhibitor on the metal's surface [61][62][63][64]. EDX was implemented to discover the elements in the MS coupons that were in contact with the aggressive solution (1M HCl) in the presence and absence of the inhibitor.…”