Anticorrosive Effect of PVP 40000 Against AISI 1020 Carbon Steel in HCl

Abstract

Polymers have received considerable attention for replacing synthetic inorganic and organic anti-corrosion inhibitors since they are not as toxic for the environment, besides being cheaper. Polyvinylpyrrolidone (PVP) has been studied due to its applicability, solubility, very low toxicity, cost and efficiency in corrosion inhibition against metals, such as zinc, aluminum, stainless steel, and others. Its anti-corrosion activity with 40000 g mol-1 was tested against AISI 1020 carbon steel in 0.5 mol L-1 HCl, and evaluated by electrochemical techniques: Potentiodynamic Polarization (PP), Linear Polarization Resistance (LPR), and Electrochemical Impedance Spectroscopy (EIS). The maximum efficiency was 90% and 89% in EIS and LPR, respectively, at concentration of 1.0 x 10-7 mol L-1. The adsorption mechanism was coherent with Langmuir isotherm model. The morphology of the corroding carbon steel surface, in the presence and absence of the PVP, was visualized using Scanning Electron Microscopy (SEM).

Application of a Mix of Vegetables Residues as Inhibitor for Carbon Steel

“…It is the most utilized steel with carbon content below 2%, which is considered a material of high added value, used in several sectors, due to its wide applicability and also for having advantageous mechanical properties for engineering applications 25 . Its chemical composition (%) is formed by: C = 0.17; Mn = 0.30; P = 0.04; S = 0.05 e Fe = 0.44 26 . The 1020 carbon steel samples were used in dimensions of 20 x 20 x 8 mm.…”

“…The band at 1465 cm -1 is characterized by the vibration of C=C double bonds present in aromatic rings [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] . At 1161 cm -1 there is another peak that can be attributed to the vibrations of aromatic rings, which according to Santos (2017) 9 , they come from phenolic groups (tocopherols, flavonoids, and tannins), which are adsorbed on the metallic surface to form a planar layer, resulting from the interaction of π electrons of the molecule with the metal 37 .…”

“…The chemical characterization of CBP and PKCP obtained by FTIR (Figures 1 and 2) revealed the presence of aromatic rings and functional groups containing nitrogen, oxygen, and carbon in their structures, as well as electronegative functional groups, which explains their antioxidant and inhibitory properties [38][39] . The inhibitory action of these organic compounds can be attributed to their interactions with the metal surface through an adsorption process [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] . The generated film can act as a barrier between the metal and the electrolyte, so the inhibition efficiency can be related to the chemical characteristics of the adsorbed layer 41 .…”

Extrato De Hibisco-Colibri Como Inibidor Verde De Corrosão Do Aço-Carbono Em Ácido Sulfúrico

“…O grau de cobertura (θ) é diretamente proporcional à eficiência de inibição da corrosão e pode ser calculado de acordo com a Equação 2. 10,21,22 (2) em que W 0 e W são as taxas de corrosão na ausência e presença de inibidor, respectivamente.…”

“…Na presença de extrato (Figura 6A), a superfície é homogênea e com menor rugosidade, confirmando o caráter inibidor do extrato, observado nos ensaios gravimétricos. [21][22][23] CONCLUSÃO O extrato de M. arboreus apresentou boa eficiência de inibição da corrosão frente ao aço-carbono AISI 1020 em meio de ácido sulfúrico 1 mol L -1 . Nos estudos de eficiência em função do tempo de imersão o extrato apresentou 97,5% de eficiência de inibição da corrosão, nos tempos de 3 h, 24 h e 48 h, na temperatura de 30 °C e concentração de 500 ppm.…”