Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2-mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings

A new series of N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides (designated as NTA‐n, n = 8, 10, 12, 14, and 16) were synthesized. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization showed that NTA‐n could protect availably X70 steel from attack of HCl with an inhibition efficiency of about 95%. And the inhibition ability follows the following sequence: NTA‐8 < NTA‐10 < NTA‐12 < NTA‐14 < NTA‐16, suggesting that prolonging alkyl chain may enhance the inhibition capacity of the molecules. Theoretical investigation backs up well the experiment results. The correlation of theoretical calculation with the experiment results illustrated clearly double logarithmic relations between the corrosion current and the computed quantum chemical parameters such as the highest occupied molecular orbital energy ( E HOMO), energy gap (ΔE), molecular volume ( ν), electronegativity ( χ), the total energy of iron crystal with the adsorbed inhibitor molecule ( E total), the interaction energy of Fe (1 0 0) surface and inhibitor molecules ( E inhibitor), while an equation resembling Hammet relation was existed between the corrosion currents and the fraction of electrons transfer (ΔN). These linear correlations suggest the relation of the inhibitor structure with its inhibition activity: long alkyl chain and electron donating groups in NTA‐n will enhance the corrosion efficiency.

show abstract

“…The

E_{interaction}

between Fe (1 0 0) surface and the inhibitor molecule was calculated with following formula:

{italicE}_{interaction} = {italicE}_{total} - ({italicE}_{surface} + {italicE}_{Inhibitor}),

where

E_{total}

is the total energy of iron crystal together with the adsorbed inhibitor molecule,

E_{surface}

and

E_{Inhibitor}

are the energy of Fe (1 0 0) surface and inhibitor molecules, respectively.…”

Section: Experimental Methodsmentioning

confidence: 99%

New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation

Chen

Jiang

Cheng

et al. 2019

Materials & Corrosion

View full text Add to dashboard Cite

show abstract

“…One explanation lies in improved cathodic inhibition, provided by the formation of a tightly bound protective film. Whilst the presence of such a film was first described by Uhlig in 1955 13 , and has been confirmed by numerous authors since 10 , 14 , 15 , its formation is not well understood, since polyphosphates are expected to revert to orthophosphates by hydrolysis under the alkaline conditions at cathodic sites. Nonetheless, it is widely accepted that film quality determines inhibitor efficiency at the cathode.…”

Section: Introductionmentioning

confidence: 93%

The Unexpected Role of Carbonate Impurities in Polyphosphate Corrosion Inhibition

Morsch

Emad

Farren

et al. 2018

Sci Rep

View full text Add to dashboard Cite

Polyphosphate corrosion inhibitors are increasingly marketed as chromate replacements for coil coated steel. The mechanisms underpinning corrosion prevention by these species is, however, not fully understood; corrosion inhibition is ordinarily assessed using electrochemical techniques, followed by ex-situ surface analysis. As a result, the formation of a clear film over cathodic sites is known to contribute to corrosion prevention, but little is known about its formation. Here, we apply advanced microscopy techniques (in-situ fluid cell AFM, SEM-EDX, and AFM-IR nano-chemical analysis) to examine early cathodic film formation by strontium aluminium polyphosphate (SAPP) in detail. For a model cut edge system, it is found that cathodic inhibition dominates during the first 24 hours of immersion, and surprisingly, that strontium carbonate impurities play a significant role. Rapidly precipitated zinc carbonate provides protection almost immediately after immersion, before the film structure evolves to include (poly)phosphate species. This suggests that the purposeful inclusion of carbonates may provide a new, environmentally sound approach to enhancing inhibitor efficacy.

show abstract

“…The corrosion of mild steel is a basic technological problems for many industries because of the high economic losses that occur because of metal degradation . Three possible methods, including cathodic protection, anodic protection, and polymer coating, have been suggested to protect metal surfaces from corrosive attacks . Epoxy (EP) coatings have received remarkable interest as polymer‐based coatings in various industries because of their good barrier properties against corrosive species, good adhesive properties, low cost, and high strength .…”

Section: Introductionmentioning

confidence: 99%

Epoxy coating with self‐healing capability based on a 2‐mercaptobenzothiazole‐loaded CeO₂nanocontainer

Hosseini

Aboutalebi

2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

In this study, we demonstrated a facile approach for the synthesis of nanocontainers using the encapsulation of a 2‐mercaptobenzothiazole (MBT) inhibitor; these nanocontainers were capable of responsively releasing a corrosion inhibitor and of self‐healing performances. The anticorrosive performance of the CeO2 nanocontainers was investigated with electrochemical impedance spectroscopy (EIS) measurement in a saline electrolyte via the incorporation of different weight percentages (0.5, 1, and 2 wt %) of synthesized nanocontainer in epoxy (EP) resin. The EIS results show that the loading of 1 wt % CeO2 nanocontainer containing MBT inhibitor in the epoxy (EP) coating [EP/NC MBT–CeO2 (1%)] provided the highest Rcoat, the lowest constant phase element of coating, and the optimum release of MBT at different operating pHs. The highest coating resistance Rcoat values of this coating (7.81 × 107 Ω cm2) were about 12 and 8573 times greater than those considered for EP–CeO2 and EP coatings, respectively. Different releases of the MBT inhibitor were detected at various pHs. We found that the coating operating in acidic media exhibited a better self‐healing performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47297.

show abstract

Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2-mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings

Abstract: Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings. Corrosion Science,

Cited by 85 publications

References 43 publications

New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation

New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation

The Unexpected Role of Carbonate Impurities in Polyphosphate Corrosion Inhibition

Epoxy coating with self‐healing capability based on a 2‐mercaptobenzothiazole‐loaded CeO₂nanocontainer

Contact Info

Product

Resources

About

Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2-mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings

Abstract: Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings. Corrosion Science,

Cited by 85 publications

References 43 publications

New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation

New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation

The Unexpected Role of Carbonate Impurities in Polyphosphate Corrosion Inhibition

Epoxy coating with self‐healing capability based on a 2‐mercaptobenzothiazole‐loaded CeO2nanocontainer

Contact Info

Product

Resources

About

Epoxy coating with self‐healing capability based on a 2‐mercaptobenzothiazole‐loaded CeO₂nanocontainer