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The effect of different kind of pigments on the corrosion resistance properties of an epoxy paint has been investigated using electrochemical impedance spectroscopy and open circuit potential measurements. Painted naval steel samples were studied during the exposure to artificial sea water. The epoxy paint coatings were prepared employing red lead, zinc, red iron oxide or titanium dioxide as pigment with 0.8 of PVC/CPVC ratio. From the EIS and corrosion potential data analyis was found that the anticorrosive protection given by an anticorrosive (pigmented with red lead) and a top coat (pigmented with red iron oxide) epoxy painting scheme was both more lasting and more effective. This was attributed to the fact that both the effective adhesion provided by the chemical bonding between the steel surface and the epoxy paint groups and the constant high barrier effect afforded by this type of top coat were a perfect complement for the high corrosion inhibitive capacity of the red lead pigment.

The effect of different kind of pigments on the corrosion resistance properties of an epoxy paint has been investigated using electrochemical impedance spectroscopy and open circuit potential measurements. Painted naval steel samples were studied during the exposure to artificial sea water. The epoxy paint coatings were prepared employing red lead, zinc, red iron oxide or titanium dioxide as pigment with 0.8 of PVC/CPVC ratio. From the EIS and corrosion potential data analyis was found that the anticorrosive protection given by an anticorrosive (pigmented with red lead) and a top coat (pigmented with red iron oxide) epoxy painting scheme was both more lasting and more effective. This was attributed to the fact that both the effective adhesion provided by the chemical bonding between the steel surface and the epoxy paint groups and the constant high barrier effect afforded by this type of top coat were a perfect complement for the high corrosion inhibitive capacity of the red lead pigment.

An electrochemical impedance spectroscopy technique based on an equivalent circuit used for the evaluation of metallic substratum/organic coating/electrolyte systems as well as the importance of each parameter and the way to calculate it is analysed. It is emphasised that the classical semi circumference in the complex plot, which describes the response of a parallel RC circuit, is not real axis centred. This fact makes it necessary to consider the organic film and electrochemical double layer capacitance as pseudo‐capacitances which depend on a fractional power of the frequency. Starting from mathematical relationships over the total impedance algorithms based on the least squares methods are proposed to fit experimental data requiring less processing time than iterative techniques. The methodology is described analysing the charge transfer resistance, ionic resistance and dielectric capacitance variation at increasing immersion times for naval steel/chlorinated rubber (with different PVC)/artificial sea water systems. Parameters thus obtained correlate well with the naval steel/organic coating deterioration with time, also determined by using corrosion potential measurements and visual assessment.

Health and safety legislation has forced changes in the type of anticorrosive pigments used in paint formulations, mainly focused on their substitution with different phosphates. The zinc phosphate pigment used with different types of binders has provided contradictory experimental results. In this paper, waterborne anticorrosive paints pigmented with zinc phosphates were studied. The main variables considered were PVC and the anticorrosive pigment content. Accelerated tests (salt spray, humidity chamber, and electrochemical tests) were performed to evaluate the paints’ anticorrosive performance. Good correlation was found using salt spray and impedance tests. From analysis of the time dependence of all the experimental results it was concluded that an efficient steel protection could be obtained using a waterborne epoxy primer pigmented with zinc phosphate. Such protection is attained through the barrier effect afforded by the paint film as well as the precipitation of a pretty stable ferric phosphate layer under the intact and damaged coating areas.

Mathematical correlations For obtaining the described parameters, the general model of equivalent circuit used in studying painted metals must be simplified. Within a determined range of high enough frequencies the impedance afforded by Cm is small, therefore, the simplified circuit is reduced as shown in Fig. 18.

Substitution of zinc chromate or zinc yellow, traditionally used as anticorrosive pigment, for other phosphate‐based pigments that are not hazardous to health and have the same anticorrosive behaviour or even better, is studied in this paper. Four alkyd paints were specially prepared; two of them contained calcium acid phosphate or micronised zinc phosphate as anticorrosive pigments respectively. A paint containing zinc chromate was used as reference and a paint without anticorrosive pigments was used as a blank, in which the other ingredients were increased proportionally to attain the desired PVC relationship. The corrosion behaviour of low carbon steel panels coated with these paints in a 3 per cent NaCl solution was assessed by electrochemical impedance spectroscopy (EIS). In addition, other painted panels were evaluated by salt spray and humidity chamber tests. Results of all tests showed that the paint with calcium acid phosphate and especially that with micronised zinc phosphate exhibited better behaviour than paint with zinc chromate. Analysis of impedance parameters (ionic resistance and capacitance of the paint film) against immersion time allowed the paints to be ranked in the same order as that obtained with salt spray and humidity chamber tests.

This paper aims to investigate effect of porous polystyrene microspheres encapsulated inhibitor on the protection performance of epoxy resin coating.

Porous polystyrene (PS) microspheres were synthesized by soap-free emulsion polymerization. The morphology of microspheres was observed by scanning electron microscopy and transmission electron microscopy. Corrosion inhibitor benzotriazole was encapsulated into porous PS microspheres. The protection performance of epoxy resin coating with different contents of PS microspheres was tested by polarization curve.

The findings of electrochemical impedance spectroscopy and scanning vibrating electrode technique showed that addition of corrosion inhibitor to porous PS microspheres further improved the protection performance of the coatings.

Porous PS microspheres could be used as nanocontainer to encapsulate corrosion inhibitor.

Addition of porous PS microspheres with corrosion inhibitor improved the protection performance of the coatings.

This 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.

The 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.

The 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.

In 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.

These paints could be used for the protection of metal structures in low corrosive environments.

There are not many published works using zeolites as anticorrosive pigments.

To identify the dependence of the anticorrosion efficiency of chemically varying pigments on their concentration in steel protecting paints.

Anticorrosion pigments from a group of nontoxic substances were chosen and compared with a chromate pigment. With all pigments, the following parameters were observed namely, oil absorption, critical pigment volume concentration value, density, extract pH, specific surface, particle size, water‐borne substances content, and the specific electrical conductivity of pigment extracts. The aqueous extracts of pigments were used to determine the corrosion loss of steel. The morphology of pigment particles was observed by means of an electron‐scanning microscope. Paints containing these pigments were formulated on the binder basis of an epoxy resin. The paints prepared were subjected to measurement of physical‐mechanical properties such as hardness and resistance in deep drawing. Paints containing anticorrosion pigments were subjected to corrosion tests in a SO₂ condenser chamber, salt spray cabinet and to a test according to Machu and Schiffman.

The experimental investigations revealed the absolute values of the anticorrosion effects of individual pigments as well as dependence of efficiency on the concentration of the pigments in the paints. It was found that environment‐friendly pigments achieved comparable or even better anticorrosion efficiency than toxic strontium chromate.

The anticorrosion properties of the paints concerned can be tested in paints by means of atmospheric exposure such as the Florida test.

The results find their application in the formulation of anticorrosion paints for industrial applications with environment‐friendly effects.

This research paper presents the results of the anticorrosion effects of a great number of industrially used pigments. Based on this paper, the formulation of highly effective steel‐protecting paints can be optimised.

The aim of this study was to evaluate the corrosion inhibition efficiency of steel samples in different environments before and after the treatment with rust metamorphose (RM), which is formulated in this research study and shows excellent adherence over the rusted surface of substrate because of the presence of the P-O-Fe bond.

An RM solution (phosphorylated polyphenol) was synthesised and characterised using Fourier transform infrared spectroscopy (FT-IR), and then the degree of protection offered by it to steel surfaces with and without the treatment with the RM solution in different atmospheres was evaluated;. Before and after treating with the RM solution, the corroded steel samples were characterised using X-ray diffraction (XRD), FT-IR, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The study of the passive behaviours of the corroded steel samples and RM-treated steel samples was done in different simulated atmospheres.

This RM solution is phosphorylated polyphenol solution (proved by FT-IR), which acts as a corrosion inhibitor on corroded steel surfaces because of the formation of a passive and symmetric adherent layer of phosphorylated polyphenol–iron complex (confirmed by FT-IR, XRD, EDS, SEM and adhesion X test). The significant improvement in corrosion resistance in splash conditions of 3.5 per cent NaCl, tap water and 1.5 per cent Na₂SO₄ was found with the treatment of phosphorylated polyphenol-based RM.

The development of RM and its characterisation with performance evaluation in different atmospheres is a novel approach in this research.