Anticorrosive Pigments Research Articles

Corrosion Performance of Steel Bar Embedded in Seawater Mixed Mortar with Batching Plant Waste

Reinforcing steel deterioration is complicated by corrosion. Reinforcing steel corrosion can weaken a structure. Corrosion cannot be eliminated; however, it can be reduced to increase building service life. The objective of the research it to demonstrate the effect of coating method as corrosion prevention and the cover depth to the corrosion performance of steel bar embedded in seawater mixed mortar. This study examines the corrosion rate of steel reinforcement in a 15 x 15 x 15 cm mortar cube made by using seawater as mixing water and containing Portland Pozzolan Cement (PPC) as a binder material. This study also experiences numerous corrosion mitigation methods using wet, dry, and dry-wet cycle exposure methods. The reinforcement and mortar surface were protected with anti-corrosive paint. Additionally, specimens without protective measures were also fabricated for comparison. Two reinforcing steels were attached in the two different cover depths, 3 cm and 5 cm. This study used sand and batching plant byproducts as fine aggregate. Study found a hierarchy of corrosion-causing exposures. The dry-wet cycle was the most corrosive, followed by wet and dry. Steel coating prevents corrosion better than surface coating. However, both methods outperformed the uncoated method in corrosion resistance. The mortar cover was 5 cm thick, compared to 3 cm expected. A combination of mortar with fine sand aggregate outperformed dry mortar made from batching plant leftovers. The investigation of corrosion potential through the utilization of the half-cell potential technique reveals that the outcomes obtained from test specimens using the steel coating prevention approach exhibit a higher degree of positivity in comparison to the prevention method including surface coating. The unprotected approach exhibits outcomes that lean towards being more unfavorable compared to the steel coating prevention method and the surface coating prevention method. The findings indicate that the performance of reinforcing steel embedded within a 3 cm mortar cover depth is often worse when compared to reinforcing steel situated inside a 5 cm mortar cover depth.

Analysis of the functional additives effect on the corrosion resistance of paint coatings

The paper deals with the issue of protecting metals from corrosion, which can damage their structures. Anti-corrosion coatings are widely used to ensure the durability of steel structures. It was described that the durability of the coating depends on the chemical and physical characteristics of the system, such as the type of coating, dry film thickness, water resistance, and adhesion. The importance of artificial aging tests for assessing the durability of coatings is considered, emphasizing that the results of such tests should be interpreted with caution, taking in consideration that artificial aging may not have the same effect as natural exposure. Various anti-corrosion additives for acrylic water-dispersion enamels are also described, which can improve the corrosion resistance of the coating, depending on the service conditions. The object of the research is the properties of enamels with functional additives in salt fog. The study results of the effectiveness of the anti-corrosion additives in acrylic enamels using salt fog from the BGD 881/S chamber are discussed. The research showed that the main requirement for increasing the effectiveness of the anti-corrosion additive in acrylic LPM is a comprehensive approach to improvement of the coating barrier properties, which additionally reduces the aggressive influence of the environment. The advantages of new complex anti-corrosion additives compared to traditional anti-corrosion pigments are multifunctionality – complex additives like Askonium 142 DA contain several active components that affect various coating properties, including anti-corrosion protection, adhesion, and water resistance. Traditional pigments, such as zinc phosphate, usually have only one function – to create a protective film on the metal. The main research idea of the article is to study the influence of anti-corrosion additives in paint coatings for metal protection from corrosion and the extension of the service life of structures.

A comprehensive investigation of oxygen/graphite carbon nitride smart Nano coatings for sustainable maintenance and sacrificial anode protection of mild steel

AbstractBACKGROUNDThis study enhancing the corrosion resistance of mild steel (MS) by incorporating photo‐catalyst‐doped graphitic carbon nitride (g‐C₃N₄) nano‐sheets containing silver (Ag) and oxygen (O₂) into a solar light‐active photoelectrochemical anticorrosion paint with polyester (PE). The objective is to provide sacrificial anode protection through visible light activation.RESULTSThe developed paint forms a uniform film on the MS surface, effectively providing anodic protection under visible light. Characterization techniques, including energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy, confirm the molecular structure of the nano‐sheets. Corrosion resistance, assessed through weight loss measurements and open circuit potential (OCP) tests, shows significant improvement with the addition of Ag/g‐C₃N₄ and Ag‐O₂/g‐C₃N₄ nano‐sheets at an optimized concentration of 15 mg. The protection efficiency is ranked as follows: O₂‐g/C₃N₄ > O‐g/C₃N₄ > Ag‐O₂/g‐C₃N₄ > Ag‐g/C₃N₄ > g‐C₃N₄. After 28 days of immersion in seawater, MS coated with O₂/g‐C₃N₄ exhibited the least weight loss, with an inhibition efficiency of up to 99%. Electrochemical impedance spectroscopy (EIS) further demonstrated enhanced coating resistance for the O₂/g‐C₃N₄ coating (Rct = 3.76 kΩ.cm2, Rcoat = 1.69 kΩ.cm2) compared to pure PE (Rct = 0.005 kΩ.cm2, Rcoat = 0.096 kΩ.cm2).CONCLUSIONThe synthesized O₂/g‐C₃N₄ and Ag‐O₂/g‐C₃N₄ nano‐sheets exhibit high surface areas and enhanced water dispersibility, which contribute to significant corrosion protection of MS. The electrochemical performance, including weight loss and OCP measurements, highlights the potential of these nano‐sheet photo‐catalysts in advancing corrosion resistance technologies, with broad implications for materials science and engineering applications. © 2024 Society of Chemical Industry (SCI).

Anticorrosive pigment for smart and green protective coatings: An alkyd resin coating incorporating lanthanum-loaded hydroxyapatite, derived from a phosphate mining industry by-product

Intelligent anti-corrosive coatings have gained considerable interest as a method to protect metals. This approach offers an effective strategy for mitigating corrosion by providing advanced control over the process. In this research, lanthanum-loaded hydroxyapatite pigment (La-HAp) was successfully synthesized using phosphate sludge (PS) waste. The pigment was incorporated into an alkyd resin coating to provide smart corrosion protection for mild steel exposed to a saline solution. The synthesized pigments were characterized using various analytical techniques, including FTIR, XRD, and SEM−EDS. The inhibitory performance of La-HAp on mild steel submerged in a 3% NaCl solution was evaluated using linear polarization and EIS techniques. The findings demonstrated substantial inhibitory effectiveness, achieving 82% inhibition efficiency. Further investigation compared the protective capabilities of modified (C-La-HAp) and reference (C-Ref) alkyd coatings on carbon steel using EIS. The results indicated significant corrosion protection enhancement with 5% La-HAp, showing a polarization resistance of 19.7 MΩ·cm2 after four weeks of immersion in the aggressive solution. This corrosion resistance is primarily attributed to the formation of a barrier against the corrosive environment and the trapping of Cl- ions by the HAp, accompanied by the release of La, phosphate, and calcium ions. La ions react with OH- ions produced in the cathodic zones to form a uniform protective layer of Lahydroxides, while iron orthophosphates provide additional protection at anodic sites. This synergistic blend of mechanisms imparts intelligent corrosion-inhibiting properties to the alkyd resin, effectively guarding against the damaging effects of corrosive agents.

Anticorrosion mechanism of epoxy coating containing mesoporous resorcinol-formaldehyde hollow nanosphere loaded with 8-Hydroxyquinolin

Mesoporous resorcinol-formaldehyde hollow nanosphere (MRFHN) with erythrocyte like shape was prepared successfully. The average diameter, shell thickness, and specific area of MRFHN are 223 nm, 42 nm, and 73.2 m2/g, respectively. The average loading capacity of 8-Hydroxyquinoline (8-HQ) in MRFHN is 33 % and the sucked 8-HQ can release continuously from MRFHN. MRFHN loaded with 8-HQ (MRFHN@8-HQ) was introduced into epoxy coating to enhance its anticorrosion performance. The results show that epoxy coating pigmented with MRFHN@8-HQ has a higher anticorrosion performance than neat epoxy coating. Especially, epoxy coating containing 4 wt% of MRFHN@8-HQ presents the best anticorrosion performance and self-healing function, and its coating resistance is still maintained at 109 Ω cm2 even after 50-day immersion in 3.5 wt% NaCl solution. Meanwhile, the scratch on coating surface is covered by a thin layer of 8-HQ which can prevent the AA2024 aluminum alloy from corrosion even after 50-day neutral salt spray test. 8-HQ can release from MRFHN and form a compact inhibiting layer on AA2024 aluminum alloy surface, thus the corrosion of AA2024 aluminum alloy is suppressed effectively. MRFHN@8-HQ can be used as a high performance anticorrosion pigment to give epoxy coating a long term protection.

Evaluation of the anticorrosive painting procedure with reused abrasive for surface preparation – a case study

Atmospheric corrosion is a relevant cause of failure for many metallic structures. Its aggressiveness depends on environmental factors such as relative humidity, salinity, and contaminants. Anti-corrosion paint is the most used technique to minimize this problem, and surface preparation is a fundamental step for suitable paint adhesion. Abrasive blasting can remove oxides and old paint and texture the surface for receiving a new coating. An alternative to reduce costs is reusing abrasive particles to make the process more sustainable. In this investigation, an paint system was qualified through tests in its current environment. The influence of reused abrasives on the painting process by the paint layer’s thickness and its adhesion to the substrate was evaluated. Samples blasted with new and reused abrasives were prepared to evaluate the surface preparation process, allowing surface roughness measurements and incrustation analysis. It was possible to observe that the layers of paint were thin and not uniform, had approximately 155 μm thick, and defects such as pinholes. Reusing the abrasive did not affect the surface average roughness, which was 9.4 ± 2.5 μm. Abrasive incrustation and other contaminants such as Na, P, K, S, and Cl were found on new and reused abrasive surfaces. Recommendations for improvement and suggestions for changing the process were possible to assess.

Study of Anti-Corosion Properties of Pigments Fe2O3-Al2O3-MgO Obtained by Coprecipitation

Promising pigments of the passivating type, in addition to phosphate ones, are other materials - oxyhydroxides, ferrites, molybdates, stanates, borates, tungstates, which are obtained using traditional technologies. condition. Researchers are becoming increasingly interested in the co-precipitation method, which makes it possible to vary the cationic and anionic composition of pigments and obtain nanodispersed products. In addition, developers of paints and varnishes are faced with the task of replacing toxic anti-corrosion chromium-, cadmium- and plumbum-containing pigments that are part of most modern inhibitory primers with pigments that are safe for human health. An alternative to such paint and varnish materials are oxide type fillers, which are anti-corrosion pigments, including oxyhydroxides, magnesium ferrites, cobalt aluminates, zinc ferrites, copper ferrites, magnesium aluminates, zinc aluminates, etc. The color of pigments and their anticorrosion properties depend on the chromophore ions included in the structure of the resulting compounds.Co-precipitation technology has a number of advantages over traditional ones and can radically reduce the cost of producing oxide materials. This process, based on the use of the internal chemical energy of the system, allows synthesis to be carried out at reduced temperatures, synthesis duration and energy costs. The simplicity of the equipment, the possibility of synthesizing a significant amount of the product of the desired phase and granulometric composition, and the environmental friendliness of the process also indicate the feasibility of using this method. Recently, attempts have been made to obtain pigments by co-precipitation, but no systematic studies have been carried out on the final products. The resulting products were in most cases poorly reproducible. In this regard, it becomes interesting to synthesize in a mode that would make it possible to obtain pigments with good color characteristics in a finely dispersed state, and eliminate the labor-intensive grinding stage, study the conditions for the formation of pigments with the structure of oxyhydroxides, the influence of their composition on color and anti-corrosion properties, study the patterns of formation of anti-corrosion properties, development of compositions for producing pigments using the co-precipitation method and subsequent heat treatment. Through experimental and theoretical studies, the influence of the nature of chromophore cations on the color tone, color purity, and anti-corrosion properties of pigments in the Fe-Al-Mg-O system has been established, which allows for the targeted synthesis of beige, red and yellow pigments with high anti-corrosion properties. The main technological properties of pigments are determined by the composition of metal-containing anions. The anti-corrosion properties of oxyhydroxide pigments are largely determined by the presence of hydroxide ions formed due to dissociation. The greatest effect is observed in the case of using metal compounds whose dissociation constants differ significantly. The protective effect is mainly determined by the slowdown of the anodic process. At the same time, anions containing aluminum atoms accelerate corrosion processes.

Durability of anticorrosive-coated steel–carbon fiber reinforced polymer structural adhesive joint at high temperature and humidity

Limited information on the long-term reliability of structural adhesive joints hinders their practical application. Moreover, performance improvement in transportation equipment and the solution of concrete problems, such as high strengthening, vibration reduction, and weight saving, are expected by increasing the availability of materials in the shipbuilding industry using highly functional materials that are not welded. This study evaluated the durability of second-generation acrylic (SGA) structural adhesives. The strength of SGA was higher than that of epoxy-based adhesives in the case of thick adhesive layers, and few fluctuations were observed in the strength owing to variations in the adhesive-layer thickness. The static strength following environmental degradation was evaluated using a tensile lap shear structural adhesive joint coated with an anticorrosive coating, assuming application to the exposed part. The acceptable design adhesive strength in shipbuilding was evaluated using the strength retention rate ηd (mean strength after deterioration/initial mean strength) and coefficient of variation CV (standard deviation/mean strength) after deterioration. ηd for each test was greater than 72 %. The CV value for each test was <0.16; this is equivalent to a coefficient of dispersion of deterioration Dy ≥ 0.41 on percent defects allowed = 1/10,000 (upper limit of the defect rate assumed at the design stage). This result indicates that the adhesive joint is available even for the exposure section, if the adhesive joint is protected similar to adherend steel with anticorrosive paint, which is common in the field of shipbuilding.

Коррозионно-электрохимические исследования стали марки Ст3 с различными видами обработки

Fires at the petrochemical industry facilities cause harm to human life and health and significant economic and environmental damage. Accidents associated with ignitions at oil and petrochemical storage facilities in 2018–2022, resulted in injuries of 21 persons, and 10 fatalities; the total economic damage exceeded 1.5 billion rubles. One of the causes of fires is the spontaneous combustion of pyrophoric corrosive deposits (17 %). As a result of the reaction of the interaction of iron disulfide with oxygen in the air, pyrophoric corrosive deposits ignite. Large-scale steel equipment containing sulfurous oil is exposed during operation to corrosive and mechanical wear, risk of fires, and explosions. One of the protection methods of oil and gas equipment against corrosion and pyrophoric formations is surface treatment with paint anticorrosive coating. Modern paint coatings proved to be ineffective in ensuring anticorrosive protection of metal equipment. The main objective of the article is to study various options of metal surface treatment by electrochemical methods with the following comparison of their protective ability. The efficiency (isolating ability) of various treatments of St3 steel has been analyzed. Based on the results of electrochemical corrosive studies, chronogalvanometric curves have been built. Therefore, to determine the efficiency of the protective effect of anticorrosive paint coatings, the accelerated corrosive-electrochemical method is recommended. For the treatment of the oil equipment surface, the anticorrosive paint coating containing the following layers: inhibitor (urotropinу solution); primer (sodium polyacrylate, ethyl alcohol); and two layers of sodium polyacrylate, have been proposed to use. The application of this protective coating will ensure a fault-free mode of operation of oil equipment for more than 10 years without coating replacement. This will guarantee the safe work of employees at the petrochemical industry facilities.

Intercalation of decanoate anions (C10) in layered double hydroxide Mg[sbnd]Al and its application as controlled-release corrosion inhibitor of steel

This study focuses on the preparation and characterization of a novel anticorrosion pigment based on decanoate anions (C10‐) intercalated within layered double hydroxide (LDH) MgAl. The LDH-NO3, LDH-C10 were synthesized by a simple co-precipitation method and analyzed by XRD, infrared spectroscopy, thermogravimetry and electronic microscopy. The LDH-C10 pigment with a basal distance of about 20 Å was consistent with the arrangement of C10 anions in bilayer. The inhibition efficiency of the LDH-C10 pigment in electrolyte and in alkyd resin paint was studied by electrochemical impedance spectroscopy and potentiodynamic techniques. The pigments act as a C10− nanocontainer, which release the C10− anions in contact with chloride ions that lead to the formation of a passive layer on steel. In alkyd resin, the LDH-C10-enriched organic coating exhibit very interesting anticorrosive performance in NaCl electrolyte during 40 days of immersion.

A wide range of modified alkyd resins based on a new source of dicarboxylic acid as a binder for anticorrosive paint

Purpose This paper aims to prepare alkyd protective paint by using modified alkyd with 3,6-dichloro benzo[b]thiophene-2-carbonyl glutamic acid (DCBTGA) as a source of dicarboxylic acid and evaluating their anticorrosive properties compared with those of unmodified alkyd coatings for steel protection. Design/methodology/approach Short, medium and long oil alkyds, which represented as (0, 10, 20 and 30% excess-OH) according to the resin constants (Patton, 1962), were prepared through a condensation polymerization reaction via a solvent process in a one-step reaction. The modification of alkyd was carried out by using DCBTGA as a source of dicarboxylic acid. The prepared modified alkyd was confirmed by IR and NMR spectral analysis. The physicochemical, mechanical and anticorrosion performance properties of the considered modified coating formulations against unmodified blank coating were studied to confirm their application efficiency. Findings The best results in terms of physicochemical, mechanical and anticorrosion performance properties were found according to the following of this order activity: 30 replacements of the modifier (DCBTGA) for each hydroxyl continent were 30% Ex-OH &gt; 20% Ex-OH &gt; 10% Ex-OH &gt; 0% Ex-OH, compared with that formulation containing unmodified alkyd, especially with increasing the modifier percent. Originality/value The prepared DCBTGA-modified resins can be used for different applications based on the type of alkyd and application.

Graphene nanosheet reinforcement of polyurethane nanocomposite for green and sustainable photoluminescence, superhydrophobic, and anticorrosive paint.

A simple and environmentally friendly method was developed for smart and efficient waterborne polyurethane (PUR) paint. Sugarcane bagasse was recycled into reduced graphene oxide nanosheets (rGONSs). Both lanthanide-doped aluminate nanoparticles (LAN; photoluminescent agent, 7-9nm) and rGONSs (reinforcement agent) were integrated into a waterborne polyurethane to produce a novel photoluminescent, hydrophobic, and anticorrosive nanocomposite coating. Using ferrocene-based oxidation under masked circumstances, graphene oxide nanosheets were produced from sugarcane bagasse. The oxidized semicarbazide (SCB) nanostructures were integrated into polyurethane coatings as a drying, anticorrosion, and crosslinking agent. Polyurethane coatings with varying amounts of phosphor pigment were prepared and subsequently applied to mild steel. The produced paints (LAN/rGONSs@PUR) were tested for their hydrophobicity, hardness, and scratch resistance. Commission Internationale de l'éclairage (CIE) Laboratory parameters and photoluminescence analysis established the opacity and colourimetric properties of the nanocomposite coatings. When excited at 365 nm, the luminescent transparent paints emitted a strong greenish light at 517 nm. The anticorrosion characteristics of the coated steel were investigated. The phosphor-containing (11% w/w) polyurethane coatings displayed the most pronounced anticorrosion capability and long-persistent luminosity. The prepared waterborne polyurethane paints were very photostable and durable.

Effect of Zeolite-Phosphate Anti-Corrosion Pigment on Protective Properties of Epoxy Coating on Carbon Steel

Effect of Zeolite-Phosphate Anti-Corrosion Pigment on Protective Properties of Epoxy Coating on Carbon Steel

Review of the Application of Gravimetric and Electrochemical Techniques to Evaluate Corrosion Mechanisms in Metal Materials

Corrosion in carbon steels is a phenomenon that causes degradation of mechanical properties; iron alloys are susceptible to corrosion. Factors such as changes in temperature, pH of the medium, and humidity accelerate the corrosion process, and the oxides formed can generate irreversible changes to the material. The evaluation of surface corrosion is necessary to be able to predict in time, to be able to provide good maintenance whether by coatings, inhibitors, or anticorrosive paints, in an opportune way, and to avoid large economic and structural losses. Gravimetric techniques such as mass loss and electrochemical techniques such as Open Circuit Potential-OCP and Electrochemical Impedance Spectroscopy-EIS, help understand the different corrosion mechanisms, simulate real conditions, and generate reproducible studies with efficiency of time and interpretation. This work shows a brief review of gravimetric and electrochemical techniques applied to the evaluation of corrosion of carbon steels.

Anti-corrosion resistance of coatings based on powder epoxy paints containing modifiers

The corrosion resistance of coatings (thickness 70 µm) based on epoxy powder paints modified with aliphatic amine or a mixture of anticorrosive pigments to the action of sodium chloride solution and salt spray has been studied. It is showed that with the increase of molecuar weight of initial epoxy oligomer and also at the incorporation of chemisorbing alifatic amine, containing polar groups, to the decrease in the permeability of the sodium chloride solution into the coating material is observed. It has been established that the observed changes in the properties of the coatings are due to the formation of a spatial structure of the polymer with different cross-link frequencies. It is shown that the introduction of a mixture of anti-corrosion pigments into the composition of paints provides a significant increase in the protective properties of coatings and a high preservation of the physical and mechanical properties of coatings in comparison with the base compositions. For 9000 hours of testing in a sodium chloride solution, the strength characteristics of the coatings decrease by about 10–12 % from the original ones. Based on the results of tests of coatings to the action of salt spray, the possibility of using the developed epoxy powder paints for operation in environments of a high atmospheric-corrosive category – C 5–1, including the application of coatings directly on a metal surface (Direct to metal) without multi-stage preparation of the metal surface for painting, is shown.

Chemical analysis of marine microdebris pollution in macroalgae from the coastal areas of Argentina

Marine microdebris (MDs, <5 mm) and mesodebris (MesDs, 5–25 mm), consist of various components, including microplastics (MPs), antifouling or anticorrosive paint particles (APPs), and metallic particles (Mmps), among others. The accumulation of these anthropogenic particles in macroalgae could have significant implications within coastal ecosystems because of the role of macroalgae as primary producers and their subsequent transfer within the trophic chain. Therefore, the objectives of this study were to determine the abundance of MDs and MesDs pollution in different species of macroalgae (P. morrowii, C. rubrum, Ulva spp., and B. minima) and in surface waters from the Southwest Atlantic coast of Argentina to evaluate the ecological damage. MDs and MesDs were chemically characterized using μ-FTIR and SEM/EDX to identify, and assess their environmental impact based on their composition and degree of pollution by MPs, calculating the Polymer Hazard Index (PHI). The prevalence of MDs was higher in foliose species, followed by filamentous and tubular ones, ranging from 0 to 1.22 items/g w.w. for MPs and 0 to 0.85 items/g w.w. for APPs. It was found that macroalgae accumulate a higher proportion of high-density polymers like PAN and PES, as well as APPs based on alkyd, PMMA, and PE resins, whereas a predominance of CE was observed in surrounding waters. Potentially toxic elements, such as Cr, Cu, and Ti, were detected in APPs and MPs, along with the presence of epiplastic communities on the surface of APPs. According to PHI, the presence of high hazard score polymers, such as PAN and PA, increased the overall risk of MP pollution in macroalgae compared to surrounding waters. This study provided a baseline for MDs and MesDs abundance in macroalgae as well as understanding the environmental impact of this debris and their bioaccumulation in the primary link of the coastal trophic chain.

The Calcium Gluconate Filled Epoxy Waterborne Primer Coating for Marine Application

The synthesis of corrosion protection in the waterborne epoxy primer coating, which included calcium gluconate (CG), was synthesized. Various compositions of CG, ranging from 0 to 8 grams were applied to the carbon steel substrate using this water-based epoxy coating. The investigations included FTIR characterization, Tafel plot polarization, immersion, adhesion, and hardness tests. The presence of CG at 2868.88 cm-1, corresponding to calcium ion (Ca2+), was confirmed by the FTIR result, while the epoxy functional group was detected at 1506 cm-1. Furthermore, it was observed that the immersion test, hardness test, and adhesion test revealed that the highest formulation for corrosion inhibition was 8 g of CG, which also exhibited a lower corrosion rate of 0.262 mmpy, improved mechanical properties (4H), and 0 % area removed. The presence of CG, which facilitated interaction with the epoxy resin through coordination between gluconate ions and Ca2+ ions, was believed to be responsible for increasing the concentration of dissolved Ca2+ ions in the solution. This, in turn, enhanced the formation of Ca(OH)2 on the surface of the aluminium alloy, leading to corrosion inhibition. Ultimately, the utilization of CG as an anti-corrosive pigment resulted in a reduction of corrosive properties and an enhancement of mechanical properties in waterborne primer coatings.

Polyolefin-Based Smart Self-Healing Composite Coatings Modified with Calcium Carbonate and Sodium Alginate.

Corrosion-related damage incurs significant capital costs in many industries. In this study, an anti-corrosive pigment was synthesized by modifying calcium carbonate with sodium alginate (SA), and smart self-healing coatings were synthesized by reinforcing the anti-corrosive pigments into a polyolefin matrix. Structural changes during the synthesis of the anti-corrosive pigment were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Moreover, thermal gravimetric analysis confirmed the loading of the corrosion inhibitor, and electrochemical impedance spectroscopic analysis revealed a stable impedance value, confirming the improved corrosion resistance of the modified polyolefin coatings. The incorporation of the anticorrosive pigment into a polyolefin matrix resulted in improved pore resistance properties and capacitive behavior, indicating a good barrier property of the modified coatings. The formation of a protective film on the steel substrate reflected the adsorption of the corrosion inhibitor (SA) on the steel substrate, which further contributed to enhancing the corrosion resistance of the modified coatings. Moreover, the formation of the protective film was also analyzed by profilometry and elemental mapping analysis.

Zeolite‐Based Anti‐corrosion Pigments for Polymer Coatings: A Brief Review

The article provides a brief overview of the use of zeolites as environmentally safe anticorrosion pigments for organic coatings on metals. The number of studies on zeolite‐based inhibiting pigments has increased significantly in recent years, due to the need to replace chromates and reduce the content of phosphate corrosion inhibitors. Based on the results available in the literature, an assessment was conducted on the inhibitory properties of complex zeolite pigments obtained by various methods. Emphasis is placed on the advantages and disadvantages of ion exchange modification of zeolites with inhibitory substances and mechanochemical synthesis of pigments. Zeolites have a wide perspective in anticorrosion technologies due to their porous structure, large surface area, high pore volume, and the ability to accumulate inhibitory ions and molecules. Such properties of zeolites make possible their use for the development of self‐healing or “smart” polymer coatings. Considering the environmental safety of zeolites and their excellent thermal and chemical stability, anti‐corrosion polymer coatings inhibited by zeolite pigments could become an effective environmentally friendly alternative to chromate‐based protective coatings. The main trends and prospects for the development of research in this domain are presented.

α-Zirconium hydrogenophosphate as a nano-container of 2-aminobenzimidazole for the corrosion protection of zinc in NaCl medium.

The development of a new generation of anticorrosion pigments for paints remains an important challenge to replace the usual sparingly-soluble pigments and thus avoid the dissemination of heavy metals in the environment and the formation of holes in polymer coatings. For this purpose, α-zirconium hydrogenophosphate (Zr(HPO4)2·H2O, denoted as α-ZrP) was intercalated with the corrosion inhibitor 2-aminobenzimidazole (ABIM). Various microstructural analyses have proven the insertion of ABIM in the interlayer space by an acid-base exchange reaction and allowed us to propose a structural model for the new ABIM-ZrP pigment. The anticorrosion properties on zinc of the ABIM-ZrP, characterized by electrochemical measurements in 0.1 M NaCl, are due to the release of ABIM molecules by an ion-exchange reaction and the pH-buffer effect of α-ZrP and the amine group of ABIM. Compared to the commercial aluminium tri-phosphate (ATP) pigment, an alkyd-polymer coating loaded with the ABIM-ZrP pigment shows very interesting electrochemical behaviour by avoiding the blistering of the polymer coating and the beginning of zinc corrosion. This effect may be due to both the tortuous effect brought by the platelet shape of the pigments and the release of ABIM once the water uptake of the polymer becomes significant.