Anticorrosive Pigments Research Articles

A new approach to design of anti-corrosive three layers self-stratifying coatings

ABSTRACT A self-stratifying coating contains at least two resins of different nature, which spontaneously stratify after applying on a substrate. Various self-stratifying systems are reported in the literature, however self-starting coatings, with three layers containing anti-corrosive pigments, and their properties are rarely discussed. In this paper, self-stratifying coatings from epoxy resin and fluorinated ethylene-vinyl ether containing three pigments i.e. zinc dust, micaceous iron oxide, and titanium dioxide have cooperated in formulations. The viscosity of the total mixture has a great effect on stratification and pigment locations. Xylene as a solvent has been used for these formulations. The results show the ratio of binders and different pigment percentages in formulations has not a great effect on the stratification and location of pigments. In addition, the type of solvents with different evaporation rates does not have an effect on stratification and location of pigments in this system.

Effect of Poly (aniline-co-o-toluidine) loaded on emulsion paints with different pigments on corrosion inhibition of mild steel

Three groups of plastic emulsion paints were formulated using three different types of pigments. TiO2 was applied in the first group of paint (T-series) as a neutral pigment. Zn3(PO4)2 and Fe2O3 were added in the two other paint groups (Z-series and F-series, respectively) as anticorrosive pigments. Styrene/butyl acrylate latex was prepared by semicontinuous seeded emulsion polymerization and used as a binder in the paint formulations. Poly (ani-co-o-toluidine) (PAOT) was introduced to the painting series as an inhibitor in proportions of 0%, 1%, 2%, 3%, and 4%. PAOT inhibitor was prepared by oxidative emulsion polymerization with an equimolar amount of aniline and o-toluidine monomers. The binder and the inhibitor were tested for their particle size and chemical structure by DLS and FTIR analysis. The properties of the paint formulations were estimated physically, mechanically, and thermally. The protection efficiency of the paint coatings on steel was estimated against corrosion using an immersion test and electrochemical measurements. The DLS curves of the binder latex and the inhibitor showed a unimodal distribution of sizes 151 nm and 42 nm, respectively. However, a mix of the two emulsions exhibited a bimodal distribution of both sizes. The potentiodynamic polarization measurements showed a decrease in the corrosion current density of TiO2 coating paint from 26.4×10-7 A/cm2 to 12.3×10-7 A/cm2 in Fe2O3 coating paint. The least corrosion current density was obtained from Zn3(PO4)2 coating paint of 7.50×10-7 A/cm2. PAOT inhibitor enhanced the protection efficiency of the paint coatings with the optimum of 3%. Zn3(PO4)2 coating paint loaded with 3% PAOT inhibitor demonstrated the highest protection efficiency of 99.96%.

Fabrication of rGO-CuO and/or Ag2O nanoparticles incorporated polyvinyl acetate based mixed matrix membranes for the removal of Cr6+ from anti-corrosive paint industrial wastewater

Herein we report the fabrication of ternary system mixed matrix membranes based on polyvinyl acetate (PVAc) incorporated reduced graphene oxide (rGO) and CuO or Ag2O nanoparticles as filler in different weight ratios via non-solvent induced phase inversion separation method. The fabricated membranes were characterized for chemical composition porosity, pore distribution, surface roughness, thickness, water contact angle and mechanical strength. Scanning electron microscopy and atomic force microscopy analyses revealed that pure PVAc exhibited smooth and uniform surface while PVAc/rGO/Ag2O and PVAc/rGO/ACuO membranes possessed rough and uneven topography and higher surface porosity. PVAc/rGO/CuO and PVAc/rGo/Ag2O membranes exhibited total permeate flux of 1.60 × 10–2 g/m2 s and 1.28 × 10–2 g/m2 s corresponding to net removal of 99.9% and 98.0% respectively from model wastewater of Cr6+ under the optimized experimental conditions. Interestingly, under these optimized conditions, PVAc/rGO/CuO membrane achieved Cr6+ removal of 99.9% from anti-corrosive paint industrial wastewater (as real sample) with a flux of 1.90 × 10-2 g/m2 s, which was much higher than many state of the art membranes. The uptake of Cr6+ from real solution was confirmed by EDX and AFM analysis of the post-separation membrane. The newly designed PVAc/rGO/CuO membrane, attributed to cost-effectiveness, environmental greenness, ease of syntheisis and high efficiency, can be envisioned of potential applications for the remediation of Cr6+ and other similar pollutants from real industrial wastewater.

The Concept of Historical Aluminium-Pigmented Anticorrosive Armour Paints, for Sustainable Maintenance of Ferrous Heritage

ABSTRACT This paper describes the concept of a historical, anticorrosive paint type (armour paint), used on outdoors located ferrous substrates from the early to the mid-20th century. Synthesis from the archive and research reports findings conceptualises a 2 + 2 paint layer system. The system involves red lead linseed oil primer and a top drying oil paint pigmented with micaceous iron oxide and metallic aluminium pigments. This results in excellent barrier properties, high density and elastic paint layers. If moisture reaches the metal and paint interface, the primer acts inhibitive and passivating on the corrosion reactions. The photooxidative deterioration of the paint binder is retarded by the pigment’s ability to reflect light, which affects the lifetime of the paint system. Today, this paint concept is almost forgotten, but associated knowledge of the paint types, paint manufacturing and craft skills could contribute to a sustainable maintenance of ferrous heritage. The authentic concept is, despite its use of a red lead primer, relevant for objects with unique heritage values. The top paints could prolong the lifetime of objects already painted with red lead. A modified concept could initiate development of environmentally beneficial alternatives with VOC-free renewable binders, complex phosphate primers and zinc oxide addition.

A Preliminary Field Study of Antifouling Paint Perfomance After Short Exposure in Mandara Bali, Indonesia

Antifouling paints are applied to prevent the growth of marine biofouling. In Indonesia, that paint is widely used for ship which commonly used copper-based biocide. In fact, there is no or little comprehesive studies on antifouling paint in Indonesia compared to other tropical countries. In this study, the evaluation of the performance for antifouling paint was carried out where anticorrosion paint and bare steel were also studied as references. The measurement of corrosion rate on steel was conducted by weight loss method. The panels containing specimens were exposure up to 1-month for immersion in different depth of sea up to 3 meters. Seawater parameters consisting of temperature, pH, salinity, conductivity and dissolved oxygen were measured as well as coating properties. The results showed both surfaces of anticorrosion paint and steel specimens covered by biofouling, but not on antifouling paint. There also is not much different in antifouling paint properties before and after exposure in various depth of sea. The reduction of thickness for antifouling paint is apparently predominant to be affected by sea current. The magnitude of corrosion rate on bare steel is almost the same in different depth of sea which took place due to the effect of dissolved oxygen and biofouling. In the future, the comparison of the paints perfomance all local regions is necessary to be conducted in all local regions of the Indonesia.

ПРИМЕНЕНИЕ МОДИФИКАТОРОВ ДЛЯ ПОВЫШЕНИЯ ЭКСПЛУАТАЦИОННЫХ СВОЙСТВ ЛАКОКРАСОЧНЫХ ПОКРЫТИЙ НА ОСНОВЕ ЭПОКСИДНЫХ ПЛЕНКООБРАЗУЮЩИХ (обзор)

Epoxy oligomers are one of the most widespread synthetic polymers who during already enough long time apply to manufacturing of paint and varnish materials. Possessing number of valuable properties, epoxy paint and varnish materials have also shortcomings for which elimination use different receptions, including physical and chemical updatings using different mono- and elastomeric, silicon- and organophosphorous and other connections. The main attention is given to use of different modifiers for improvement of operational properties of anticorrosion paint coatings.

Alkyd based water-reducible anticorrosive paints and their antifungal potential

Concerns about ozone layer, contamination, fossils resources and health, has banned or restricted the use of traditionally organic solvents in paints. As a consequence, new resins that employed water as main solvent are being studied. Among these resins, alkyds are the most studied one as they can also be synthesised from natural vegetable sources, making them more acceptable.The aim of this paper was to study the anticorrosive behaviour of alkyd / polysaccharide paints containing zinc phosphate or zinc aluminum phosphate as main pigment and their performance against fungal growth. Two different PVC (pigment volume concentration) were studied. Painted panels were studied by exposition to salt spray and humidity chambers, where rusting and blistering degrees were evaluated, and by electrochemical tests (corrosion potential measurements, ionic resistances determination, linear polarization curves and polarization resistances determination).Results showed that these type of paints can be used to protect steel and that the type of pigment and the PVC are important to the protection. Besides, good selection of both also prevents fungi growth in a high humid environment.

Zirconium-Doped Ceria Nanoparticles as Anticorrosion Pigments in Waterborne Epoxy–Polymer Coatings

The use of anticorrosion pigments in polymeric coatings is an effective way for the prevention of corrosion of metals. Ceria nanoparticle-based pigments are excellent replacement for conventional c...

α-Zirconium orthophosphate as a new Zn-free anticorrosive pigment in organic coatings

In the framework of the anticorrosive pigment research without heavy metals like zinc or chromium, a new lamellar phosphate pigment, namely zirconium orthophosphate Zr(HPO4)2·H2O, was prepared by a simple precipitation route and dispersed in an organic resin coating at 5 wt.%. After characterization by electronic microscopy, X-ray diffraction and thermogravimetry, its use as a corrosion inhibitor pigment was investigated in 0.5 M NaCl corrosive media on steel and zinc. Electrochemical impedance spectroscopy measurements show that the delamination ratio of the ZrP-loaded organic coating is considerably reduced with immersion time, even though ZrP addition lowers the bulk coating resistivity. In comparison with classical aluminium triphosphate pigments, these particular high performances are related to the specific structure and physicochemical properties of ZrP materials. On the one hand, the acidity character of ZrP due to proton lability allows the control of the pH at the metal/coating interface. On the other hand, the progressive dissolution of ZrP pigments induces the formation of insoluble protective metallic phosphates and ZrO2 on zinc and steel substrates, as revealed by solution analysis (ICP-MS).

Comparative study on anticorrosion enhancement of carboxylated and sulfonated self-doped polyaniline on waterborne epoxy coating

Water-dispersed self-doped sulfonated polyaniline (SPANi) and self-doped carboxylated polyaniline (CPANi) were prepared by the copolymerization of aniline with m-aminobenzenesulfonic acid and m-aminobenzoic acid, respectively, and were identified by UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and scanning electron microscopy. The resultant SPANi and CPANi nanofibers were used as anticorrosion pigments for water epoxy coatings (EP). The corrosion resistance was compared using anticorrosive studies in 3.5 wt% NaCl solution using electrochemical impedance spectroscopy (EIS), polarization curves (Tafel), and a neutral salt spray (NSS) test. Polarization tests showed that the corrosion potential of SPANi/EP coating increased compared with CPANi/EP. EIS tests after 40-day immersion. This behavior further confirmed that the impedance modulus and coating resistance of SPANi/EP increased by three orders of magnitude compared with EP, which were two orders of magnitude higher than that of polyaniline (PANi)/EP and one order of magnitude higher than that of CPANi/EP.

New modified poly(ester amide) resins and their uses as a binder for surface coating with different applications

PurposeThis paper aims to prepare a new modified poly(ester amide) (PEA) resins and use it as a binder for anticorrosive and antimicrobial coatings.Design/methodology/approachNew modified PEA compositions were prepared based on 4-amino-N, N-bis(2-hydroxyethyl) benzamide (AHEB) as the ingredient source of the polyol used and evaluated as vehicles for surface coating. The structure of the modifier and PEA resin was confirmed by FT-IR, H¹-NMR, MW, thermogravimetric analysis and scanning electron microscope studies. Coatings of 50±5 µm thickness were applied to the surface of glass panels and mild steel strips by means of a brush. The coating performance of the resins was evaluated using international standard test methods and involved the measurement of phyisco-mechanical properties and chemical resistance.FindingsThe tests carried out revealed that the modified PEA based on AHEB enhanced both phyisco-mechanical and chemical properties. Also, the resins were incorporated within primer formulations and evaluated as anti-corrosive and antimicrobial single coatings. The results illustrate that the introduction of AHEB, within the resin structure, improved the film performance and enhances the corrosion resistance and antimicrobial activity performance of PEA resins.Practical implicationsThe modified PEA compounds can be used as binders in paint formulations to improve the chemical, physical, corrosion resistance and antimicrobial activity properties.Originality/valueModified PEA resins are cheaper and can be used to replace other more expensive binders. These modified PEA resins can compensate successfully for the presence of many the anticorrosive and antimicrobial paint formulations, and thus, lower the costs. The main advantage of these binders is that they combine the properties of both polyester and polyamide resins based on nitrogenous compound, are of lower cost and they also overcome the disadvantages of both its counterparts. Also, they can be applied in other industrial applications.

Sepiolite modified with phosphonium ionic liquids as anticorrosive pigment for epoxy coatings

The performance of sepiolite modified with different phosphonium-based ionic liquids (SepIL) as anti-corrosive pigment for epoxy resin (ER) coatings were discussed in this paper. The ionic liquids (IL) used to functionalize Sep clay mineral included trihexyl-(tetradecyl)phosphonium bistriflimide (IL1) and ethyl-tri(butyl)-phosphonium diethylphosphate (IL2) as commercial IL and the synthesized 11-carboxyundecyl-(triphenyl)-phosphonium bromide (IL3). All SepIL samples were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), elemental analysis (CHN) and X-ray diffraction (XRD). The effect of the incorporation of Sep and SepIL on the rheological properties of the ER-based dispersions and on anticorrosion properties of epoxy networks cured with isophorone diamine was investigated. The ER-based coatings loaded with Sep modified with different ionic liquids presented enhanced the anticorrosive properties with outstanding barrier properties against the diffusion of the electrolyte solution, as indicated by electrochemical impedance spectroscopy (EIS). The superior corrosion resistance of ER loaded with SepIL was also kept with scratched coating, due to the inhibition activity of the ionic liquid against corrosion process.

ПРОБЛЕМА ИСПОЛЬЗОВАНИЯ ОТХОДОВ ЛАКОКРАСОЧНЫХ МАТЕРИАЛОВ И ИХ УТИЛИЗАЦИЯ

Актуальность исследования. Коррозия металлов является наиважнейшей проблемой, с которой связаны большие потери металлов. Ежегодно от коррозии безвозвратно теряются сотни тонн металлов, поэтому все исследования, направленные на антикоррозионную защиту металлов, являются целесообразными и актуальными. Цель исследования. Существуют различные методы антикоррозионной защиты металлических деталей, но нет достаточно эффективного метода для конкретных условий антикоррозионной защиты. Целью настоящей работы является использование отходов лакокрасочных материалов для получения антикоррозионных покрытий металлических деталей. Объектом исследования являются отходы лакокрасочных материалов, полученные при окраске автомобилей. Методы: изучение физико-химических свойств отходов; подбор состава для растворения отходов лакокрасочных материалов; разработка рецептуры и получение антикоррозионной мастики; испытание полученного антикоррозионного лакокрасочного покрытия на адгезию, химостойкость, прочность пленки на изгиб, прочность пленки на удар, огнестойкость, морозостойкость; определение наиболее эффективного компонентного и количественного состава полученного покрытия. Выбраны металлические пластинки для нанесения защитного лакокрасочного покрытия, растворы различных соединений для проведения испытаний по определению потери массы опытных металлических образцов Результаты. Разработана и получена мастика на основе госсиполовой смолы и твердых отходов лакокрасочных материалов. Отходы лакокрасочных материалов – потери, получаемые при окраске автомобилей. Госсиполовая смола представляет собой отход масложиркомбината. Полученная мастика прошла испытания в лабораторных условиях по показателям качества в соответствии со стандартами, получены положительные результаты. Проведены эксплуатационные испытания в дорожных условиях, пробег автомобиля составил 12780 км, при исследовании изменения на поверхности покрытия не обнаружены.

Protective Properties of Alkyd Coatings Inhibited by Complex Zeolite-Phosphate Pigment

We study a complex anticorrosion pigment based on calcium-containing zeolite with zinc phosphate precipitated on its nanoporous surface. It is discovered that this pigment efficiently retards corrosion in an aluminum alloy placed in a synthetic acid medium and inhibits the subfilm corrosion of the metal near defects of the alkyd paint coating. The proposed pigment may serve as a promising inhibiting component of paint coatings aimed at the protection of structures made of aluminum alloy in the industrial atmosphere.

Anticorrosive paint with a modified zeolite as functional pigment for SAE 1010 steel protection

PurposeThis paper aims to formulate and prepare a series of alkyd paints with new anticorrosive pigments, eco-friendly to the environment, based on a natural zeolitic rock modified by ion exchange to incorporate passivating cations.Design/methodology/approachThe electrochemical characterization of the painted steel was carried out by conductivity measurements, linear polarization tests, measurements of the corrosion potential and electrochemical noise measurements. Besides, accelerated tests in standard environmental chambers were also carried out.FindingsThe results show that clinoptilolite–mordenite-based pigments incorporated in the paint provide acceptable anticorrosive properties, taking into account their low environmental impact and the use of a natural resource of low cost. The inhibitory efficiency of ZLa is higher than 80% and of ZPr is close to 70%. The electrochemical assays of the coated panels with the alkyd paints ZLa and ZPr shows similar behavior.Research limitations/implicationsIn this work, good results were obtained with an alkyd resin, but other resins could be tested. Paints could also be formulated with modified zeolites as a complement to others traditional anticorrosive pigments.Practical implicationsThese paints could be used for the protection of metal structures in low corrosive environments.Originality/valueThere are not many published works using zeolites as anticorrosive pigments.

Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port.

Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316 L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted toward a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in consideration for future antifouling/anti-biofilm applications.

Monitoring of biofouling communities in a Portuguese port using a combined morphological and metabarcoding approach

Marine biofouling remains an unsolved problem with a serious economic impact on several marine associated industries and constitutes a major vector for the spread of non-indigenous species (NIS). The implementation of biofouling monitoring programs allows for better fouling management and also for the early identification of NIS. However, few monitoring studies have used recent methods, such as metabarcoding, that can significantly enhance the detection of those species. Here, we employed monthly monitoring of biofouling growth on stainless steel plates in the Atlantic Port of Leixões (Northern Portugal), over one year to test the effect of commercial anti-corrosion paint in the communities. Fouling organisms were identified by combining morpho-taxonomy identification with community DNA metabarcoding using multiple markers (16S rRNA, 18S rRNA, 23S rRNA, and COI genes). The dominant colonizers found at this location were hard foulers, namely barnacles and mussels, while other groups of organisms such as cnidarians, bryozoans, and ascidians were also abundant. Regarding the temporal dynamics of the fouling communities, there was a progressive increase in the colonization of cyanobacteria, green algae, and red algae during the sampled period with the replacement of less abundant groups. The tested anticorrosion paint demonstrated to have a significant prevention effect against the biofouling community resulting in a biomass reduction. Our study also reports, for the first time, 29 NIS in this port, substantiating the need for the implementation of recurring biofouling monitoring programs in ports and harbours.

Anticorrosion properties of manganese-containing complex oxides, obtained by stoneware method

In recent years, in the search for alternatives to toxic anticorrosive chromium pigments, the use of complex metal oxides in this capacity has been actively developed. In this work, the anticorrosive and other physicochemical properties of complex oxides, including manganese in oxidation degrees +4 and +5, obtained by the calcination method were investigated. As a result, it has been shown that the products obtained have good prospects for being used as anti-corrosion pigments. Higher inhibitory properties of pigments containing manganese in oxidation state +5, is probably a consequence of their aqueous extract’s alkaline reaction. During the experiments, it was found that the competitiveness of the synthesized pigments can be markedly enhanced by using natural ore, pyrolusite, as manganese source.

Stratification of nano-pigments in anti-corrosive coatings by means of magnetic field

The concept of self-stratification of coatings, although attractive, causes difficulties in its practical use, especially when pigments are added to the resins. An alternative way of obtaining a multilayer structure in a single step was presented. Using the inhomogeneous magnetic field and magnetically active components of the coating, the possibility of vertically graded differentiation of the one layer properties has been verified. For this purpose, the magnetic properties of nickel ferrite (NiFe2O4) nano-particles and magnetic field for their transport in a wet coating were used.It has been shown that it is possible to use the magnetic field to transport magnetic ferrite, used as active anti-corrosive pigments, near the coating/substrate interface, in the initially homogeneous wet paint layer, during film formation. These results prove that magnetic ferrite pigments can be magnetically manipulated in liquid coating layer applied on the substrate. Using the impedance spectroscopy technique, it was possible to detect stratification by analyzing complex capacity diagrams. As a result of impedance tests, better anti-corrosive properties of the system hardened in the presence of the magnetic field were demonstrated.

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