Peumus boldusextract as corrosion inhibitor for carbon steel in 0.5 M sulfuric acid

Abstract

The methanolic extract of Peumus boldus (P. boldus) has been studied as a potential green corrosion inhibitor for carbon steel in 0.5 M H 2 SO 4 using gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy tests at 25, 40 and 60°C, and concentrations of 0, 0.1, 0.3, 0.5, 0.7 and 1.0 g/L. Results indicate that P. boldus is physically adsorbed onto the steel surface and acts as a mixed corrosion inhibitor of carbon steel corrosion. The data fitted best to the Temkin adsorption isotherm. The inhibition efficiency of P. boldus extracts was observed to increase with increasing its concentration but decreases on increasing the test temperature. The inhibitive effect is attributed to the presence of vitamin E, Limonene and eucalyptol in the extract.

The use ofBrugmansia arboreaas a green corrosion inhibitor for AISI 1018 carbon steel in acid media

“…In Figure 4, the obtained equivalent circuit is shown; where R s is the solution resistance, R ct is the charge transfer resistance, CPE is the constant phase element to model the condenser non-ideality and R f corresponds to the resistance given by the inhibitor layer and/or by the corrosion products (34). This type of circuit suppose that the inhibitor forms a faulty layer onto the metal, acting as an effective obstacle before the aggressive media of the acid solution, that is why the corrosion process is controlled by a mechanism that occurs in the non-protected metal, with a much reduced active surface, this type of circuit has been used in many studies to analyze EIS obtained data by other inhibitors in which a second capacitive semicircle is formed (35)(36)(37)(38)(39)(40).…”

Synthesis of 3,4,5-trihydroxy-2-[(hydroxyimino) methyl] benzoic acid as a novel rust converter

“…Metal corrosion is a serious problem all over the world and therefore a number of methods and materials have been developed to minimize the corrosion processes and environment problems (1)(2)(3)(4)(5)(6). Among the frequently reported protection methods to prevent metal corrosion, such as organic or inorganic coating (7,8), electrochemical protection (9) and corrosion inhibition (10)(11)(12)(13), the most effective and economic technique is the application of coating, particularly anticorrosive coatings (14,15). Metal surfaces require cleaning process such as acid pickling or abrasive blasting before the modification with anticorrosive coating (16).…”

Free fatty acid influenced corrosion inhibition mechanisms of some inedible plants seeds oils on low alloyed medium-carbon steel in H2SO4

“…The experimental data generated for uninhibited solution was modeled by equivalent circuit of Randles type and an improved Randles equivalent circuit which featured a two-time constant was adopted for inhibited solutions, except 0.01 g/mL SOJ. The two-time constant features are as a result of broader phase-angle shifts at mid-frequency ranges, which indicated over-lapping loops as result of protective oxide film formation due to interaction between inhibitors’ molecules and iron ions resulting in complex formation shown in equation (9) (Diaz-Cardenas et al , 2017). This complex is adsorbed on the substrate to improve protection against corrosive attack.…”