Self‐healing properties of TiO₂ particle–polymer composite coatings for protection of aluminum alloys against corrosion in seawater

Abstract

TiO 2 particle-polymer composite coatings were applied to the surface of a 5083 aluminum alloy. After using a knife to create an artificial defect, polarization resistance was monitored in artificial seawater at a temperature of 30 8C. The polarization resistance of the specimen coated with the composite polymer containing 3 vol% TiO 2 particles increased significantly over time, suggesting that the composite coating had self-healing properties. A carbon-containing 2-mm thick film was found on the coated aluminum substrate at the site of the artificial defect. The formation of the film was related to the dissolution of bisphenol A (BPA), which is a chemical precursor of the polymer coating that behaved as an inhibiting agent.

Self-healing coatings in anti-corrosion applications

“…composites which contain them belong to the materials most often used to produce self-repair coatings [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The ease of modification stems from the various properties of macromolecular compounds, such as oxidizing properties, swelling and cross-linking ability, and from the fact that no high temperatures are required to form them.…”

“…In the case of damage to the coating, bisphenol A (BPA) (one of the chemical precursors of vinylester polymer) is released. BPA reacts with aluminium, forming a barrier coating in the defective place [10]. A schematic representation of the self-healing effect of the TiO 2 particle-polymer composite coating is shown in Fig.…”

“…A schematic representation of the self-healing effect of the TiO 2 particle-polymer composite coating is shown in Fig. 3 [10]. The rutile particles present in the coatings serve as containers for BPA.…”

Micro/nanocapsules for anticorrosion coatings

“…SEM was utilized to evaluate the self-healing of epoxy coatings containing polyurethane (PU) microcapsules of hexamethylene-diisocyanate (HDI) (Huang and Yang, 2011), epoxy resins (Zhao et al, 2011), on steel surface and aluminum alloy specimen with and without TiO2 coating (Yabuki et al, 2011).…”

Gelatin microgels as a potential corrosion inhibitor carriers for self‐healing coatings: Preparation and codeposition

“…Among the self-healing coatings layers containing micro-or nano-capsules are of particular interest [4][5][6][7][8]. They consist mostly of macromolecular compounds, i.e., poly(urea-formaldehyde), epoxy resin, poly(methylmethacrylate), polystyrene [6,7,9]. The capsules may be filled with appropriately selected corrosion inhibitors, for example cerium or magnesium ions, silyl ester, linseed oil, 8-hydroxyquinoline, benzotriazole.…”