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B. Del Amo - One of the best experts on this subject based on the ideXlab platform.
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performance of anticorrosive coatings containing tripolyphosphates in aggressive environments
Industrial & Engineering Chemistry Research, 2008Co-Authors: M. C. Deyá, B. Del Amo, A. R. Sarli, R. RomagnoliAbstract:The objective of this research was to study the efficiency of calcium tripolyphosphate and zinc tripolyphosphate as anticorrosive Pigments for paints in aggressive environments. Alkyd and epoxy paints, of the solvent-borne type, containing 30% by Volume (v/v) of the Pigment, were formulated. The Pigment Volume Concentration/critical Pigment Volume Concentration (PVC/CPVC) ratio was fixed at 0.8. In a second stage, water-borne paints containing 30% v/v of both tripolyphosphates and different PVC values (20 and 25%) were also formulated. Finally, standardized accelerated (salt spray and humidity chamber exposure) and electrochemical impedance spectroscopy (EIS) tests were used to assess the protective performance of the coatings. Analysis and interpretation of the experimental data show that both, calcium and zinc tripolyphosphates, inhibit corrosion of painted steel panels exposed to aggressive environments.
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Zeolitic rock as a new Pigment for ceiling paints.: Influence of the Pigment Volume Concentration
Microporous and Mesoporous Materials, 2005Co-Authors: B. Del Amo, Cecilia Deyá, Patricia Eugenia ZalbaAbstract:Abstract The performance of a zeolitic rock, mainly clinoptilolitic (heated at 350 °C) is studied as humidity and ammonia adsorber in ceiling paints. The paints were formulated with 39% and 75% of zeolitic rock by Volume of the total Pigment content and 75% and 85% Pigment Volume Concentration (PVC). A blank, without zeolitic rock, was also formulated. The performance of the paints were assessed by gas (water and ammonia) adsorption and adsorption–desorption cycled tests. The results show that the paints containing zeolitic rock have better performance than the blank. Moreover, paints with 75% PVC behaved better than paints with PVC 85%. This behaviour may be due to the higher Pigment content because the paints with PVC 85% retain more water during the curing period diminishing their adsorption capacity.
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Zinc tripolyphosphate: An anticorrosive Pigment for paints
Surface Coatings International Part B: Coatings Transactions, 2003Co-Authors: M. Deyá, V. F. Vetere, Roberto Romagnoli, B. Del AmoAbstract:The aim of this paper was to study the efficiency of zinc tripolyphosphate as an anticorrosive Pigment for paints. A procedure to prepare the Pigment was outlined and its anticorrosive properties evaluated following the electrochemical behaviour of a steel electrode in Pigment suspensions. In a second stage, solvent-borne paints containing barium sulphate, talc and titanium dioxide together with 30 or 10% v/v (by Volume) of zinc tripolyphosphate, with respect to the total Pigment content, and PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio 0.8 were formulated. Two resins were chosen as film-forming materials: an alkyd and an epoxy-polyamide (1:1) resin. The performance of the resulting anticorrosive paints was assessed by accelerated (salt-spray and humidity chambers) and electrochemical tests (corrosion potential, ionic resistance and polarisation resistance).
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The mechanism of the anticorrosive action of calcium-exchanged silica
Surface Coatings International Part B: Coatings Transactions, 2003Co-Authors: Roberto Romagnoli, M. Deyá, B. Del AmoAbstract:The objectives of this work were to study the efficiency and the mechanism of the anticorrosive action of calcium-exchanged silica in paints. The anticorrosive properties of the Pigment were evaluated by following the electrochemical behaviour of a steel electrode in the Pigment suspension and analysing the protective layer formed on it. In a second stage, solvent-borne paints were formulated with 30% by Volume (v/v) of the total Pigment content. The selected PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio was 0.8. Two resins were chosen as film-forming materials: an alkyd and an epoxy. The performance of the resulting anticorrosive paints was assessed by accelerated (salt-spray and humidity chambers) and electrochemical tests (corrosion potential, ionic and polarisation resistance). It was demonstrated that the anticorrosive performance of paints Pigmented with calcium/silica is at least equal or better than that obtained with paints containing zinc phosphate. Good correlation was obtained between accelerated and electrochemical tests. Steel passivation by calcium-exchanged silica is a complex process accomplished by the high pH of the Pigment suspension and the deposition of a siliceous film on the steel surface.
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The influence of the anion type on the anticorrosive behaviour of inorganic phosphates
Surface & Coatings Technology, 2002Co-Authors: M. Deyá, Roberto Romagnoli, G. Blustein, B. Del AmoAbstract:The objective of this work was to study the efficiency of the anticorrosive Pigments obtained by substituting the phosphate anion in zinc phosphate with other anions such as tripolyphosphate and pyrophosphate. A procedure to prepare the Pigments is outlined and their anticorrosive properties were evaluated following the electrochemical behaviour of a steel electrode in Pigments suspensions. In a second stage, solvent-borne paints with 30% by Volume (v/v) of the Pigment, with respect of the total Pigment content, and PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio 0.8 were formulated. Two resins were chosen as film forming materials: an alkyd and an epoxy one. The performance of the resulting anticorrosive paints was assessed by accelerated (salt spray and humidity chambers) and electrochemical tests (corrosion potential, ionic resistance and polarisation resistance). It was demonstrated that the substitution of the phosphate anion by tripolyphosphate or pyrophosphate anions may give rise to effective anticorrosive Pigments for paints. The essays performed with Pigments suspensions suggested that zinc pyrophosphate has the best anticorrosive properties. The anticorrosive behaviour of the Pigments in paints was found to depend on the resin employed to formulate the coatings. Good correlation was obtained between accelerated and electrochemical tests.
M M Attar - One of the best experts on this subject based on the ideXlab platform.
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The impact of Pigment Volume Concentration on the protective performance of polyurethane coating with second generation of phosphate based anticorrosion Pigment
Progress in Organic Coatings, 2014Co-Authors: A. Darvish, Reza Naderi, M M AttarAbstract:Abstract In this study the effect of conventional zinc phosphate and zinc aluminum phosphate, which represents second generation of phosphate based anticorrosion Pigments, on the performance of a polyurethane coating was studied. While zinc phosphate modification was proved to be effective on the corrosion resistance, EIS data facilitated the determination of the optimum Pigment Volume Concentration in which the coating offered the most efficient protection. The superiority of zinc aluminum polyphosphate was attributed to the release of more inhibiting species, leading to the formation of a protective layer at the coating/substrate interface. In addition to the assessment of the impact of Pigment content on the resistance of polyurethane primer to cathodic disbonding, the dependency of adhesion strength on the Pigment type was also studied using pull-off test.
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Cathodic Delamination and Anticorrosion Performance of an Epoxy Coating Containing Nano/Micro-Sized ZnO Particles on Cr(III)-Co(II)/Cr(III)-Ni(II) Posttreated Steel Samples
CORROSION, 2013Co-Authors: Bahram Ramezanzadeh, M M AttarAbstract:In this study, a coating system including conversion coating and organic paint was used on the steel samples. The steel samples were treated by Cr(III), Cr(VI), Cr(III)-Co(II), and Cr(III)-Ni(II) conversion coatings. Epoxy coatings were reinforced with nano-zinc oxide (ZnO, 3.5 wt%) and micro-ZnO (critical Pigment Volume Concentration [CPVC]/Pigment Volume Concentration [PVC] = 0.2) particles. The epoxy coatings were applied on the steel samples treated by conversion coatings. The surface properties of the samples were studied by a contact angle measuring device. The values of dry and wet pull-off strengths of the epoxy coatings were measured using a pull-off adhesion tester. The cathodic delamination and anticorrosion performance of the epoxy coatings were investigated on the pretreated steel substrates by the cathodic disbonding test and electrochemical impedance spectroscopy (EIS), respectively. Results showed that all conversion coatings increased dry and wet pull-off strengths. The increase in pull-o...
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electrochemical study of protective behavior of organic coating Pigmented with zinc aluminum polyphosphate as a modified zinc phosphate at different Pigment Volume Concentrations
Progress in Organic Coatings, 2009Co-Authors: Reza Naderi, M M AttarAbstract:Electrochemical impedance spectroscopy was employed to evaluate protective performance of the solvent-borne epoxy coatings Pigmented with zinc aluminum polyphosphate as a representative of phosphate-based anticorrosion compounds at different Lambda values. Furthermore, the effective ratio of the Pigment Volume Concentration (PVC) to the critical Pigment Volume Concentration (CPVC) was determined. To compare the function of zinc aluminum polyphosphate and zinc phosphate incorporated into coatings, electrochemical noise method as well as electrochemical impedance spectroscopy was taken into consideration. The trend and magnitude of charge transfer, coating and noise resistances plus the amplitude of the current noise fluctuation indicated superiority of the modified Pigment. In order to provide an insight into the mechanism by which anticorrosion Pigments improve protective behavior of coating, performance of bare metals exposed to Pigment extracts was assessed through taking advantage of electrochemical impedance spectroscopy and electrochemical noise method as well.
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investigation on zinc phosphate effectiveness at different Pigment Volume Concentrations via electrochemical impedance spectroscopy
Electrochimica Acta, 2005Co-Authors: M M AttarAbstract:Abstract This research is based on studying corrosion inhibitive effect of zinc phosphate at different Pigment Volume Concentration (PVCs) in epoxy–polyamide system. EIS has been examined at open circuit potential (OCP) after 7 days of immersion in 3.5% NaCl solution to indicate electrochemical properties of epoxy coated mild steel at different levels of Pigmentation. Coating capacitance, coating resistance, double layer capacitance and charge transfer resistance have been extracted from fitting of EIS results with an electrical circuit, while impedance magnitude at 100 mHz and phase angle ( θ ) at 10 kHz have been extracted directly from bode plots. Also OCP behavior was examined. Results showed best performance at PVC = 36.5%.
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Evaluation of zinc phosphate and zinc chromate effectiveness via AC and DC methods
Progress in Organic Coatings, 2005Co-Authors: Mohammad Mahdavian, M M AttarAbstract:This research is based on studying corrosion inhibitive effect of two anticorrosive Pigments, zinc phosphate and zinc chromate. AC or electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (polarization) have been examined. At the first step, the Pigments effects on electrochemical behavior of mild steel as bare metal have been studied in the presence of 3.5% (w/w) NaCl when saturated solutions of the Pigments were prepared. At the second step, the Pigments were dispersed in the epoxy resin. Electrochemical impedance spectroscopy of epoxy coated mild steel has been investigated when they were immersed in 3.5% (w/w) NaCl solutions. Coated mild steel at the same λ (λ is the Pigment Volume Concentration to critical Pigment Volume Concentration ratio) has been fitted for both Pigmented systems with porous film model. The first and second steps comparison showed different mechanisms for the zinc phosphate when they were used in the solution and coating.
Roberto Romagnoli - One of the best experts on this subject based on the ideXlab platform.
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Zinc tripolyphosphate: An anticorrosive Pigment for paints
Surface Coatings International Part B: Coatings Transactions, 2003Co-Authors: M. Deyá, V. F. Vetere, Roberto Romagnoli, B. Del AmoAbstract:The aim of this paper was to study the efficiency of zinc tripolyphosphate as an anticorrosive Pigment for paints. A procedure to prepare the Pigment was outlined and its anticorrosive properties evaluated following the electrochemical behaviour of a steel electrode in Pigment suspensions. In a second stage, solvent-borne paints containing barium sulphate, talc and titanium dioxide together with 30 or 10% v/v (by Volume) of zinc tripolyphosphate, with respect to the total Pigment content, and PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio 0.8 were formulated. Two resins were chosen as film-forming materials: an alkyd and an epoxy-polyamide (1:1) resin. The performance of the resulting anticorrosive paints was assessed by accelerated (salt-spray and humidity chambers) and electrochemical tests (corrosion potential, ionic resistance and polarisation resistance).
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The mechanism of the anticorrosive action of calcium-exchanged silica
Surface Coatings International Part B: Coatings Transactions, 2003Co-Authors: Roberto Romagnoli, M. Deyá, B. Del AmoAbstract:The objectives of this work were to study the efficiency and the mechanism of the anticorrosive action of calcium-exchanged silica in paints. The anticorrosive properties of the Pigment were evaluated by following the electrochemical behaviour of a steel electrode in the Pigment suspension and analysing the protective layer formed on it. In a second stage, solvent-borne paints were formulated with 30% by Volume (v/v) of the total Pigment content. The selected PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio was 0.8. Two resins were chosen as film-forming materials: an alkyd and an epoxy. The performance of the resulting anticorrosive paints was assessed by accelerated (salt-spray and humidity chambers) and electrochemical tests (corrosion potential, ionic and polarisation resistance). It was demonstrated that the anticorrosive performance of paints Pigmented with calcium/silica is at least equal or better than that obtained with paints containing zinc phosphate. Good correlation was obtained between accelerated and electrochemical tests. Steel passivation by calcium-exchanged silica is a complex process accomplished by the high pH of the Pigment suspension and the deposition of a siliceous film on the steel surface.
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The influence of the anion type on the anticorrosive behaviour of inorganic phosphates
Surface & Coatings Technology, 2002Co-Authors: M. Deyá, Roberto Romagnoli, G. Blustein, B. Del AmoAbstract:The objective of this work was to study the efficiency of the anticorrosive Pigments obtained by substituting the phosphate anion in zinc phosphate with other anions such as tripolyphosphate and pyrophosphate. A procedure to prepare the Pigments is outlined and their anticorrosive properties were evaluated following the electrochemical behaviour of a steel electrode in Pigments suspensions. In a second stage, solvent-borne paints with 30% by Volume (v/v) of the Pigment, with respect of the total Pigment content, and PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio 0.8 were formulated. Two resins were chosen as film forming materials: an alkyd and an epoxy one. The performance of the resulting anticorrosive paints was assessed by accelerated (salt spray and humidity chambers) and electrochemical tests (corrosion potential, ionic resistance and polarisation resistance). It was demonstrated that the substitution of the phosphate anion by tripolyphosphate or pyrophosphate anions may give rise to effective anticorrosive Pigments for paints. The essays performed with Pigments suspensions suggested that zinc pyrophosphate has the best anticorrosive properties. The anticorrosive behaviour of the Pigments in paints was found to depend on the resin employed to formulate the coatings. Good correlation was obtained between accelerated and electrochemical tests.
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Aluminium tripolyphosphate Pigments for anticorrosive paints
Pigment & Resin Technology, 2001Co-Authors: M. Deyá, V. F. Vetere, Roberto Romagnoli, B. Del AmoAbstract:The efficiency of two anticorrosive Pigments containing aluminium polyphosphate was studied. Pigments were analysed by current analytical techniques and characterised by FT‐IR spectrometry. The anticorrosive properties of the selected Pigments were evaluated following the electrochemical behaviour of a steel electrode in Pigments suspensions. In a second stage, solvent‐borne paints with 30 and 10% v/v of the Pigment and PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio 0.8 were formulated. Three resins were chosen as film forming materials: an alkyd, an epoxy and a vinyl. The performance of the resulting anticorrosive paints was assessed by accelerated (salt spray cabinet and humidity chamber) and electrochemical tests (corrosion potential, ionic resistance and polarisation resistance). The anticorrosive performance of the tested paints was closely related with Pigment composition. The nature of the resin was also of importance; in this sense, epoxy paints showed the best anticorrosive performance. Good correlation has been obtained between accelerated and electrochemical tests.
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The influence of the solubility of zinc phosphate Pigments on their anticorrosive behaviour
Pigment & Resin Technology, 2000Co-Authors: G. Blustein, B. Del Amo, Roberto RomagnoliAbstract:The objective of this work was to study the anticorrosive behaviour of three commercial Pigments containing micronized zinc phosphate. The chemical analyses of the Pigments were carried out in the laboratory to characterise them with respect to their composition and soluble matter. It was proposed to check Pigments’ efficiency in solvent‐borne paints with 30 per cent v/v of the Pigment by Volume and a Pigment Volume Concentration/critical Pigment Volume Concentration ratio (PVC/CPVC) equal to 0.8. The behaviour of paints formulated with two binders (alkyd and epoxy) was assessed by accelerated (salt spray cabinet, humidity chamber and accelerated weathering) and electrochemical (corrosion potential, ionic resistance and polarisation resistance) tests. It was demonstrated that Pigment performance is highly influenced by their solubility which, in turn, could influence the formation of the protective layer on the metal substrate. Good correlation was obtained between salt spray and electrochemical tests.
Andrea Kalendova - One of the best experts on this subject based on the ideXlab platform.
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Corrosion protection by organic coatings containing polyaniline salts prepared by oxidative polymerization
Journal of Coatings Technology and Research, 2017Co-Authors: Miroslav Kohl, Andrea Kalendova, E. Černošková, M. Bláha, J. Stejskal, M. ErbenAbstract:The aim of this work was to describe polyaniline salts synthesized and to assess the mechanical and anticorrosion properties of alkyd resin-based coating materials Pigmented with them, in dependence on the Pigment Volume Concentration and type. Polyaniline salts were prepared by oxidative polymerization in the solutions of inorganic (hydrochloric, phosphoric, and sulfuric) and organic ( p -toluenesulfonic and 5-sulfosalicylic) acids. Polyaniline salts were characterized by thermal analysis and spectroscopic methods. Electrical conductivity was also measured by the van der Pauw method, and the molecular weight of the polyaniline was determined by gel permeation chromatography. Furthermore, the particle size of the solid salts was measured, and the morphology was studied by scanning electron microscopy. Subsequently, the parameters required to formulate Pigmented organic coatings, i.e., density and critical Pigment Volume Concentration were determined. A soybean oil-based fast drying alkyd resin of medium oil length was used as the binder for the organic coating material. Organic coatings containing the polyaniline salts at Pigment Volume Concentrations 0%, 1%, 5%, 10%, and 15% were formulated and subjected to a standard accelerated cyclic corrosion tests. The organic coatings (paint films) were also subjected to mechanical tests and to the electrochemical test by potentiodynamic polarization studies. Graphical Abstract
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Assessment of the properties of diethyl phosphite as a novel anticorrosion Pigment in organic coatings
Chemical Papers, 2017Co-Authors: Kateřina Nechvílová, Andrea Kalendova, Eva Schmidová, Patrycja BoberAbstract:The aim of this work was to provide a first description of the behaviour of diethyl phosphite in organic coatings, description of their physico-mechanical properties as well as anticorrosion properties in the protection of steel substrates. The diethyl phosphite behaviour in the organic coatings depends on the Volume Concentration of the Pigment. A polyaniline base was suspended in diethyl phosphite as a new reactant. The Pigment so prepared was used as a corrosion inhibitor in model paints containing a solvent-based epoxy-ester resin as the binder. The organic coatings were applied to steel panels and to glass panels and subjected to mechanical tests, corrosion resistance tests and electrochemical tests. Furthermore, they were exposed to the environments of condensed steam, neutral salt solution mist, and sulphur dioxide-containing mist. The corrosion effects were evaluated and the organic coatings’ overall anticorrosion efficiency was calculated from the results. Ultimately, the optimum Pigment Volume Concentration (PVC) at which the coatings provided the best anticorrosion protection was determined: it was PVC = 10 vol%, whereas the best mechanical resistance was observed at PVC = 5 vol%. The goal of the forthcoming work will be to optimise all the properties into a single Pigment Volume Concentration.
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Heteropolyacids like new anticorrosion Pigment in organic paints
Koroze a ochrana materialu, 2016Co-Authors: Kateřina Nechvílová, Andrea KalendovaAbstract:Abstract This paper is focused on the heteropoly acids as another new possibility of dopant for conducting polymers which can be used as anticorrosive Pigments for steel protection. The newly prepared Pigments, silicotungstic and phosphotungstic heteropoly acids, were characterized by determination of oil number and density. The value of critical Pigment Volume Concentration was determinated by these values. The Pigment Volume Concentration was 0.5; 1; 3 and 5 % in epoxyester-resin witch was used as a binder. Organic coatings were applicated on steel panels which were tested by mechanical and corrosion tests. The main exam was exposition of testing sample in sulphur dioxide atmosphere. Another important exam was measuring the specific electrical conductivity and determination of corrosion loss. After 1584 hours, the samples were evaluated. Values of anticorrosion efficiency are increased for silicotungstic heteropoly acid Pigment. But with long-term exposition, phosphotungstic heteropoly acid Pigment has better and higher anticorrosion efficiency than the other sample.
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Effect of polyaniline salts on the mechanical and corrosion properties of organic protective coatings
Progress in Organic Coatings, 2015Co-Authors: Miroslav Kohl, Andrea KalendovaAbstract:Abstract The aim of this work was to assess the effect of polyaniline salts (PANI-HA) with various dopant types on the mechanical and corrosion properties of organic protective coatings dependent on the Pigment Volume Concentration. The doping acids used included phosphoric acid (H 3 PO 4 ), sulphuric acid (H 2 SO 4 ), hydrochloric acid (HCl), p-toluenesulphonic acid (PTSA), and 5-sulphosalicylic acid (CAS). The polyaniline salt types were described by their physico-chemical parameters. An epoxy ester resin was used as the binder for the organic coatings. The organic protective coatings included the various PANI-HA types. The prepared organic coatings were subjected to mechanical testing, corrosion tests and linear polarisation technique. Organic coatings achieved during mechanical tests comparable results regardless of the type of PANI dopant or PVC (Pigment Volume Concentration) with the exception of organic coatings fulfilling the condition PVC = CPVC (critical Pigment Volume Concentration) which exhibited decrease of mechanical resistance. The results of accelerated corrosion tests and techniques of linear polarisation testify that in particular the PVC parameter affects the resulting corrosion resistance. During those tests, the organic coatings exhibited improved corrosion resistance, particularly at low Pigment Volume Concentrations (PVC = 0.1–5%) irrespective of the Pigment used.
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anticorrosion efficiency of organic coatings depending on the Pigment Volume Concentration of polyaniline phosphate
Progress in Organic Coatings, 2008Co-Authors: Andrea Kalendova, Irina Sapurina, David Veselý, Jaroslav StejskalAbstract:Abstract Polyaniline (PANI) was synthesized by reaction in an aqueous solution of ammonium peroxodisulfate and phosphoric acid. PANI was characterized by means of scanning electron microscopy and its physical–chemical properties were determined. Simultaneously with the synthesized PANI epoxy-ester coatings containing 3, 5, 10, 15, 20 and 24 vol.% of PANI as a corrosion inhibitor were formulated. The coatings were tested for their mechanical properties, film hardness and corrosion resistance. The testing of the anticorrosion efficiency of PANI as corrosion inhibitor was based on accelerated corrosion tests: in condensed water, NaCl mist, and condensing water and SO 2 . The prepared PANI displayed inhibition effects in corrosion reactions progressing on a steel base under the organic coating. The synthesized PANI provides good anticorrosion efficiency in an epoxy-ester coating. The studied system does not contain any heavy metals harmful to the environment.
R. Romagnoli - One of the best experts on this subject based on the ideXlab platform.
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Improvement of anticorrosive performance of phosphate-based alkyd paints with suitable additives
Journal of Coatings Technology and Research, 2011Co-Authors: G. Blustein, R. Romagnoli, M. C. Deyá, A. R. SarliAbstract:The purpose of this investigation was focused on reducing the content of zinc phosphate in anticorrosive paints by means of the incorporation of low quantities of selected soluble corrosion inhibitors. The article describes the anticorrosive behavior of alkyd paints containing reduced levels of zinc phosphate, zinc oxide, and some soluble compounds used as additives (e.g., sodium polyphosphate, sodium phosphate, and sodium benzoate). Anticorrosive solventborne alkyd paints were formulated with a zinc phosphate content of 10% by Volume (v/v) with respect to the total Pigment Concentration. In all cases, the PVC/CPVC (Pigment Volume Concentration/critical Pigment Volume Concentration) ratio was 0.8. Experimental paints, applied on sandblasted SAE 1010 panels, were evaluated by accelerated tests (salt spray cabinet) and electrochemical measurements (electrochemical impedance spectroscopy, EIS). The results show that the additions of small amounts of soluble corrosion inhibitors to low content zinc phosphate paint formulations enhance their performance in a very remarkable way. Perhaps, the most outstanding feature is that the employment of soluble additives allowed the reduction of the zinc phosphate content with concomitant savings.
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performance of anticorrosive coatings containing tripolyphosphates in aggressive environments
Industrial & Engineering Chemistry Research, 2008Co-Authors: M. C. Deyá, B. Del Amo, A. R. Sarli, R. RomagnoliAbstract:The objective of this research was to study the efficiency of calcium tripolyphosphate and zinc tripolyphosphate as anticorrosive Pigments for paints in aggressive environments. Alkyd and epoxy paints, of the solvent-borne type, containing 30% by Volume (v/v) of the Pigment, were formulated. The Pigment Volume Concentration/critical Pigment Volume Concentration (PVC/CPVC) ratio was fixed at 0.8. In a second stage, water-borne paints containing 30% v/v of both tripolyphosphates and different PVC values (20 and 25%) were also formulated. Finally, standardized accelerated (salt spray and humidity chamber exposure) and electrochemical impedance spectroscopy (EIS) tests were used to assess the protective performance of the coatings. Analysis and interpretation of the experimental data show that both, calcium and zinc tripolyphosphates, inhibit corrosion of painted steel panels exposed to aggressive environments.
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A new Pigment for smart anticorrosive coatings
Journal of Coatings Technology and Research, 2007Co-Authors: C. Deyá, R. RomagnoliAbstract:The purpose of this paper was to evaluate the performance of a modified zeolite as an anticorrosive Pigment for paints. A procedure to prepare the Pigment was outlined and its anticorrosive properties assessed following the electrochemical behavior of a steel electrode in Pigment suspension. In a second stage, alkyd paints were formulated employing different anticorrosive Pigments: (1) 30% by Volume (v/v) of the modified zeolitic rock, (2) 10% (v/v) of zinc phosphate, and (3) a mixture of 10% (v/v) zinc phosphate plus 20% (v/v) of the modified zeolitic rock. In every case, percentages were referred to the total Pigment content. Titanium dioxide, zinc oxide, and barium sulfate were incorporated to complete the Pigment formula. The Pigment Volume Concentration/critical Pigment Volume Concentration (PVC/CPVC) ratio was 0.8. The performance of the resulting anticorrosive paints was assessed by accelerated (salt spray and humidity chambers) tests and electrochemical (corrosion potential, ionic resistance, and polarization resistance) essays. It was demonstrated that the modified zeolite is effective in protecting steel from corrosion when it is used in combination with zinc phosphate. There exists a synergism between the modified zeolite and zinc phosphate that allows the zinc phosphate content in anticorrosive paints to be reduced.
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Calcium tripolyphosphate: An anticorrosive Pigment for paint
Journal of Coatings Technology, 2001Co-Authors: V. F. Vetere, R. Romagnoli, M. C. Deyá, B. Del AmoAbstract:The objective of this work was to evaluate the performance of calcium tripolyphosphate in anticorrosive paints. Its anticorrosive properties were studied in Pigment suspensions and in solventborne paints with 10% and 30% of the Pigment by Volume and a Pigment Volume Concentration/critical Pigment Volume Concentration (PVC/CPVC) equal to 0.8. The behavior of paints formulated with epoxy and alkyd resins was assessed by accelerated (salt spray cabinet and humidity chamber) and electrochemical tests (corrosion potential, ionic resistance, and polarization resistance).
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Calcium tripolyphosphate: An anticorrosive Pigment for paint
Journal of Coatings Technology, 2001Co-Authors: V. F. Vetere, M. C. Deyá, R. RomagnoliAbstract:The objective of this work was to evaluate the performance of calcium tripolyphosphate in anticorrosive paints. Its anticorrosive properties were studied in Pigment suspensions and in solventborne paints with 10% and 30% of the Pigment by Volume and a Pigment Volume Concentration/critical Pigment Volume Concentration (PVC/CPVC) equal to 0.8. The behavior of paints formulated with epoxy and alkyd resins was assessed by accelerated (salt spray cabinet and humidity chamber) and electrochemical tests (corrosion potential, ionic resistance, and polarization resistance). Calcium tripolyphosphate was proven to inhibit steel corrosion when incorporated in a paint film. Good protection was achieved employing only 10% by Volume of the Pigment, instead of 30%, as was suggested in the case of phosphates. The anticorrosion protection afforded by alkyd paints was impaired when the Pigment content was increased. Epoxy paints seemed to be less sensitive to the Pigment content.