Electrochemical and structural properties of a polyurethane coating on steel substrates for corrosion protection

González-García, Yaiza; González, S.; Souto, Ricardo M.

doi:10.1016/j.corsci.2007.03.018

Cited by 192 publications

(74 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This spectrum can be numerically fitted by an equivalent electrical circuit (EEC) consisting of a capacitor and a resistor in parallel. The capacitor represents the coating capacitance (Ccoat) and the resistor the pore resistance (Rpore) as commonly described in literature (Walter, 1986;Amirudin and Thieny, 1995;González-García et al, 2007;Bastos et al, 2010;Hauffman et al, 2013). When the barrier is disrupted, the effect of the underlying layers becomes visible.…”

Section: First Self-healing Action: Effect Of Mbtmentioning

confidence: 99%

“…The second one, which is initially less pronounced, shows the effects at the metal-solution interface. A double layer capacitance (Cdl) and a charge transfer resistance (Rct) of the corrosion reaction are commonly used to describe these effects of the passivation layer (Walter, 1986;Amirudin and Thieny, 1995;González-García et al, 2007;Bastos et al, 2010;Hauffman et al, 2013). To account for imperfections of the real systems constant phase elements have generally been used instead of pure capacitances.…”

Section: First Self-healing Action: Effect Of Mbtmentioning

confidence: 99%

See 1 more Smart Citation

A Multiple-Action Self-Healing Coating

et al. 2016

View full text Add to dashboard Cite

This article describes a self-healing coating for corrosion protection of metals, which combines two different types of self-healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT) was loaded into layered double hydroxide (LDH) carriers that were mixed into an acrylated polycaprolactone polyurethane-based shape-recovery coating and applied on hot-dip galvanized steel (HDG). The effect of triggered release of MBT on the protection of HDG became visible when samples with manually applied defects in the coating were immersed in 0.05 M NaCl solution (first, autonomous-healing mechanism). The shape recovery (second, non-autonomous-healing mechanism) was triggered by heating the samples for 2 min to 60°C. SEM-EDX and Raman spectroscopy proved the presence of MBT in the LDH, in the MBT-loaded LDH in the coating and the released MBT on the HDG surface in the damaged area after being in contact with a solution containing corrosive ions. Electrochemical impedance spectroscopy and scanning vibrating electrode technique demonstrate the corrosion protection effect of MBT in the coating with a defect and the restoration of the barrier properties of the coating after defect closure. This way, the independent mechanisms of this multi-action self-healing coating could be demonstrated.

show abstract

Section: First Self-healing Action: Effect Of Mbtmentioning

confidence: 99%

Section: First Self-healing Action: Effect Of Mbtmentioning

confidence: 99%

A Multiple-Action Self-Healing Coating

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Furthermore, on steel and concrete in chemical, pulp and paper, power and other industries due to their good hardness combined with excellent adhesion to metallic substrates, anticorrosive properties and weather resistance [51][52][53][54]. By all of these reasons, such paints have been studied by several authors, who determined variations of coating porosity resistance, coatings dielectric capacitance, polarization resistance, double layer capacitance [55][56][57] and also the relationship between electrolyte diffusion through the paint coat and the corrosion resistance of the underlying metal [12,58].…”

Section: Introductionmentioning

confidence: 99%

Characterization and Corrosion Resistance of Galvanized Steel/Passivation Composite/ Polyurethane Paint Systems

Sarli¹,

Elsner²,

Tomachuk³

2014

BJAST

View full text Add to dashboard Cite

The corrosion performance of electrogalvanised steel sheets pre-treated with a Cr 3+ or Cr +6 -based conversion layer and then covered with polyurethane-waterborne topcoat paint has been studied. The pre-treated metallic panels were coated with one of the three tested polyurethane (PU) topcoat paints, in which the dispersion type was the formulation variable. The pigment was TiO 2 (rutile) with a PVC value of 10. Before and after the immersion in 0.05 M NaCl (pH 5.70) or 0.1 M Na 2 SO 4 (pH 6.36) solutions, replicates of the different samples were subjected to standardized tests (porosity, gloss and color, hardness, flexibility). During the immersion, blistering and rusting degrees were evaluated through periodical visual inspections, while the coated steel performance was monitored by Electrochemical Impedance Spectroscopy (EIS) measurements. Initial (dry) and final (wet) paint adhesion was also determined. EIS data were interpreted and discussed in terms of the time dependence of the electrical (paint coating) and electrochemical (steel substrate) parameters associated with interfacial processes describing the metal/paint system deterioration. According to the electrochemical properties, visual inspection and Original Research ArticleBritish Journal of Applied Science & Technology, 4(6): 853-878, 2014 854 standardized tests results, it was concluded that the studied polyurethane-based polymeric films applied on pretreated electrogalvanised steel provided a very effective protection against corrosion as a result of their excellent barrier properties.

show abstract

“…4 However all polymeric coatings are permeable to corrosive species such as oxygen, water and ions to some extent. [5][6][7][8] Water molecules at the metal/coating interface may reduce the coating adhesion, thus favoring corrosion of the metal underneath the film.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Investigation into the Effect of Nano-Titania on the Protective Properties of Epoxy Coatings on Mild Steel in Natural Seawater

Raj¹

2017

IPCSE

View full text Add to dashboard Cite

The effect of introducing nano-tinania (TiO 2 ) particles to the epoxy coatings on mild steel in natural seawater was analyzed using Scanning Electrochemical Microscopy (SECM) and Electrochemical Impedance Spectroscopy (EIS). Line profile and topographic image analysis were measured by applying -0.70 V and +0.60 V as the tip potential for the cathodic and anodic reactions, respectively. The tip current at -0.70 V for the epoxy coated sample with TiO 2 nanoparticles decreased rapidly due to cathodic reduction of dissolved oxygen. The EIS measurements were conducted in natural seawater after wet and dry cyclic corrosion test. The EIS measured the film resistance (R f ) and charge transfer resistance (R ct ) values which were increased by the addition of TiO 2 nanoparticles in the epoxy coating. SEM/EDX and FIB-TEM analysis showed that complex oxides of titania were enriched in corrosion products at the scratched area of the coated steel and confirmed the presence of the nanoscale oxide layers of titania in the rust of the steel. The formation of complex oxides of titania had a beneficial effect on the corrosion resistance of coated steel. Keywords Electrochemical investigation into the effect of nano-titania on the protective properties of epoxy coatings on mild steel in natural seawater 144Copyright: ©2017 Raj et al. Nanoparticles, owing to high specific surface area and small particle size, can enhance the corrosion resistance of the organic coatings by increasing the electrolyte pathways length. Inclusion of metal nanoparticles to the organic coating provides cathodic protection to the underlying substrate. They also provide barrier and passive protection by generating oxides at a later stage. The importance of nanomaterials compared to conventional micro sized pigments is mainly due to their small size and large specific surface area. The decrease in size of the particles causes mechanical properties enhancement of the coating. There are a large number of reports indicating that the anticorrosion properties of the polyurethane coatings can be markedly improved in the presence of nanoparticles. Citation9-16 Titanium oxide is highly corrosion resistant and provides a barrier protection which is stable over a wide pH range. It is not classified as dangerous for human health and for environment. This has shown interest in using titanium oxide in organic coatings in the corrosion protection of steel. SECM has been introduced to evaluate the localized corrosion process, since it provides electrochemical activity and topographic information about the surface reactions at the micrometer scale in aqueous environments. [17][18][19][20][21] The application of SECM has facilitated experiments on the solid/liquid interface because of its high spatial resolution and electrochemical sensitivity.In this study, SECM was used primarily to evaluate the effect of TiO 2 nanoparticles on the corrosion protection performance of an epoxy coating over mild steel in natural seawater. The tip current was detected during the cor...

show abstract

Electrochemical and structural properties of a polyurethane coating on steel substrates for corrosion protection

Cited by 192 publications

References 18 publications

A Multiple-Action Self-Healing Coating

A Multiple-Action Self-Healing Coating

Characterization and Corrosion Resistance of Galvanized Steel/Passivation Composite/ Polyurethane Paint Systems

Electrochemical Investigation into the Effect of Nano-Titania on the Protective Properties of Epoxy Coatings on Mild Steel in Natural Seawater

Contact Info

Product

Resources

About