Self-healing coatings in anti-corrosion applications (original) (raw)

Self-Healing Coatings for Corrosion Inhibition of Metals

Modern Applied Science, 2015

Anti-corrosion protective coatings have been widely applied as a surface treatment to prevent corrosion ofvarious metallic materials, such as aluminum alloys, magnesium alloys, steel and zinc-coated steel, which areused in automobile parts, building structures, home appliances, etc. One of the most important characteristics ofthese coatings is the ability to self-heal. If a self-healing coating suffers mechanical damage and corrosivespecies in the environment begin to degrade the bare metal surface, the damaged surface is automaticallyrepaired by a chemical component of the coating. Chromate conversion coatings have self-healing properties.However, environmental concerns have necessitated the reduction and discontinuation of chromate-basedprotective coatings in recent years. This paper describes two recently developed self-healing coatings — afluorine polymer coating with metal particles and a coating comprised of particles and an organic healing agent.A fluorine polymer coating has...

Corrosion-resistant self-healing coatings

AIP Conference Proceedings, 2018

The use of polymeric coatings with self-healing ability is a viable approach for a new smart corrosion protection strategy. Polymer systems are usually applied on a metal surface to provide an effective barrier against the corrosive species. The protective coatings have to delay the inexorable water uptake, blister or crack formation and delamination. Among self-repairing polymers, in this area of interest, Diels-Alder epoxy resins are particularly appealing for coating application, because the products and intermediates obtained during the healing treatment are stable to aggressive environments, such as the major oxidation agents, air and water. In addition, the chemical stability and crosslinked structure of epoxies are preserved and ensure the coating functionality. An intrinsic mendable epoxy system, containing bifunctional adducts, has been prepared by Diels-Alder reaction. Optical microscopy and nanoindention tests validated the morphological and structural recovery of the coating. Immersion test in saline solution revealed the complete restoration of the corrosion protection for a healed sample.The use of polymeric coatings with self-healing ability is a viable approach for a new smart corrosion protection strategy. Polymer systems are usually applied on a metal surface to provide an effective barrier against the corrosive species. The protective coatings have to delay the inexorable water uptake, blister or crack formation and delamination. Among self-repairing polymers, in this area of interest, Diels-Alder epoxy resins are particularly appealing for coating application, because the products and intermediates obtained during the healing treatment are stable to aggressive environments, such as the major oxidation agents, air and water. In addition, the chemical stability and crosslinked structure of epoxies are preserved and ensure the coating functionality. An intrinsic mendable epoxy system, containing bifunctional adducts, has been prepared by Diels-Alder reaction. Optical microscopy and nanoindention tests validated the morphological and structural recovery of the coating. Immersion test in...

Development and Performance Evaluation of Corrosion Resistance Self-Healing Coating

ISRN Corrosion, 2014

Polymer based nanocapsule was developed using core-cell approach, where the core material was methyl diphenyl diisocyanate and the cell material was urea-formaldehyde. The synthesized capsules of 100 to 800 nm size were incorporated into sol-gel matrix to prepare a final coating for steel protection. This coating was found protecting the steel at the damage or crack locations in 3.5% NaCl solution. SEM micrographs confirmed healing of the coating at the damage or crack points.

A Multiple-Action Self-Healing Coating

Frontiers in Materials, 2016

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.

Self-healing coating systems for corrosion protection

… Conference on Self …

The requirements for a self healing primer paint system are discussed in terms of the general aspects of inhibitor formulation and delivery to a defect in a paint system. For repeated healing of the underlying metal it is necessary to have triggered release of the inhibitor. This can be obtained through the delivery system which might be designed to respond to external triggers such as mechanical damage, moisture or chloride concentration.

The influence of size and healing content on the performance of extrinsic self‐healing coatings

Journal of Applied Polymer Science, 2020

Among the several approaches for the protection of metallic structures from corrosion, covering with a polymeric coating has attracted more attention due to their convenient application, cost-effective price, and the relatively benign environmental impact. However, the polymeric coatings are sensitive to mechanical/thermal shocks and aggressive environments, leading to damages in the coatings that affect their barrier performance. Self-healing polymeric coatings have introduced remarkable development by extending the service life and reducing maintenance costs, leading to a significant boost in the reliability and durability of the conventional polymeric coatings. Among the different strategies to develop self-polymeric coatings, encapsulating healing agent within micro/nanocapsules, micro/nanofibers, and microvascular systems and incorporating them within the conventional coatings have been widely acknowledged as the most applicable approach. However, several factors, such as the effect of the healing system's size and content, have a significant influence on healing performance. Therefore, this review aims to reveal the effects of healing system size and healing content on the self-healing performance in polymeric coatings through the analysis of recently published articles. K E Y W O R D S coatings, surfaces and interfaces, resins 1 | INTRODUCTION In most industries, metals are utilized due to their superior physical and mechanical properties. However, metal structures are usually affected by corrosion, wear, and erosion, which cause high financial damages. According to the World Corrosion Organization (WCO), the global annual cost of corrosion is approximately 3.1%-3.5% of a country's gross domestic product (GDP). 1 The situation is more critical when the metallic structures are used as

Thermally Mendable Self-Healing Epoxy Coating for Corrosion Protection in Marine Environments

Materials

Polymeric coatings represent a well-established protection system that provides a barrier between a metallic substrate and the environment. The development of a smart organic coating for the protection of metallic structures in marine and offshore applications is a challenge. In the present study, we investigated the use of self-healing epoxy as an organic coating suitable for metallic substrates. The self-healing epoxy was obtained by mixing Diels–Alder (D–A) adducts with a commercial diglycidyl ether of bisphenol-A (DGEBA) monomer. The resin recovery feature was assessed through morphological observation, spectroscopic analysis, and mechanical and nanoindentation tests. Barrier properties and anti-corrosion performance were evaluated through electrochemical impedance spectroscopy (EIS). The film on a metallic substrate was scratched and subsequently repaired using proper thermal treatment. The morphological and structural analysis confirmed that the coating restored its pristine p...

Self-Healing Performance of Multifunctional Polymeric Smart Coatings

2019

Multifunctional nanocomposite coatings were synthesized by reinforcing a polymeric matrix with halloysite nanotubes (HNTs) loaded with corrosion inhibitor (NaNO3) and urea formaldehyde microcapsules (UFMCs) encapsulated with a self-healing agent (linseed oil (LO)). The developed polymeric nanocomposite coatings were applied on the polished mild steel substrate using the doctor’s blade technique. The structural (FTIR, XPS) and thermogravimetric (TGA) analyses reveal the loading of HNTs with NaNO3 and encapsulation of UFMCs with linseed oil. It was observed that self-release of the inhibitor from HNTs in response to pH change was a time dependent process. Nanocomposite coatings demonstrate decent self-healing effects in response to the external controlled mechanical damage. Electrochemical impedance spectroscopic analysis (EIS) indicates promising anticorrosive performance of novel nanocomposite coatings. Observed corrosion resistance of the developed smart coatings may be attributed ...

Multifunctional self-healing polymeric nanocomposite coatings for corrosion inhibition of steel

Surface and Coatings Technology, 2019

The present work focuses on the self-healing and corrosion behavior of novel epoxy based coatings containing epoxy monomer (EM) and dodecylamine (DDA) as self-healing and corrosion inhibitor, respectively. The coating self-healing ability and the corrosion inhibition effect have been combined, together, in one single coated layer providing autonomous corrosion protection. Towards this goal, the as-synthesized titania nanotubes (TNTs), with an average size of 20 nm were impregnated with DDA and EM and were thoroughly dispersed into the epoxy used as the matrix and applied on steel. Fourier-transform infrared spectroscopy (FTIR) analysis confirms the presence of DDA loaded nanotubes and the loading of inhibitor was estimated by thermogravimetric analysis.. Additionally, the amount of the released corrosion inhibitor was identified by gas chromatography-mass spectrometry (GC-MS). The scanning electron microscopy (SEM), analysis shows the polymer healing of the prepared coatings when damaged. The electrochemical studies indicate that the corrosion rate of the steel samples coated with the epoxy modified with the healing additives decreases after 5 days of immersion in saline water.