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

Abstract

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.

Thickness Dependence of Contact Angles in Multilayered Ultrathin Polymer Films

“…Examples include glass-transition temperature ( T g ), − density, , refractive index, , wetting/dewetting behavior, − and many others. , Among these polymer material properties, the wettability of ultrathin films is less explored, perhaps because of the difficulty of conducting a systematic study on homogeneous ultrathin polymer films, but no less important. The wetting behavior of ultrathin polymer films is critical knowledge for the design of tailored wettability in performance coatings from flexible electronics, water collection, antifouling, to self-healing …”

Reversible hetero-Diels–Alder amine hardener as drop-in replacement for healable epoxy coatings

“…Healable materials have the inherent capacity to repair physical and/or chemical damage to regain their integrity and associated properties, [1][2][3][4][5][6][7] following two main strategies: extrinsic [8][9][10][11] and intrinsic healing. [12][13][14][15] The former relies on pre-assembled healing agents (such as unreacted monomer, catalyst and solvent), which are incorporated into the material during fabrication.…”

Encapsulation of Cerium Nitrate within Poly(urea-formaldehyde) Microcapsules for the Development of Self-Healing Epoxy-Based Coating

“…Because of some shortcomings in the barrier performance of the organic coatings, they have been not considered as the tailored barriers. Therefore, any defects caused by chemical and mechanical factors may provide direct access to corrosive agents to the metal surface. − However, one of the key challenges of the coating technology is how the organic coatings can be formulated for a high-performance anticorrosive system on metal structures. Self-healing systems have been introduced to address the aforementioned shortcomings, while the release of healing agents showed a long-term protective effect. − The incorporation of self-healing agents in organic coatings leads to a high-performance system with excellent protective properties against mechanical damages and corrosive agents. − In these systems, after creating environmental damage, they have the ability to recover their initial properties. − White et al achieved the first practical demonstration in the field of self-healing materials.…”