## 1 Introduction  
Offshore drilling platforms are exposed to salt-containing and high-humidity environments for a long period of time and face serious metal corrosion problems [1, 2]. In order to cope with these problems, anti-corrosion coatings are usually applied to the platform's steel structure to slow down the corrosion process [3]. However, the coating is prone to microcracking during service due to mechanical stress caused by deformation of the mechanical structure [4], aging caused by ultraviolet rays [5], etc., exposing the metal substrate and forming seawater infiltration channels, thereby accelerating metal corrosion. As corrosion intensifies, the coating may peel off, leading to a failure of its protective function [6]. The microcapsule-based self-healing coating offers a novel approach to coating repair [7]. This method endows the coating with self-repairing capabilities by encapsulating repair materials, such as repair agents, within capsules [8, 9, 10]. When the coating surface cracks or is damaged, the repair material in the microcapsules is released to fill the damaged areas. By promptly repairing the damage to the coating, it can effectively prevent the expansion of corrosion caused by microcracks, scratches, or localized damage [11]. When applied in harsh marine environments, it can enhance the durability and reliability of the coating [12]. Currently, the commonly used methods for preparing self-healing microcapsules include interfacial polymerization [13], in situ polymerization [14], emulsion polymerization. [15]. Among them, the interfacial polymerization method is a technique for preparing microcapsules by separately dissolving monomers in oil and water phases, promoting the emulsification of the oil-water two phases with emulsifiers, and utilizing the polymerization reaction at the oil-water interface to form microcapsule shells [16]. At present, several studies and applications of microcapsules prepared by interfacial polymerization have been explored in the field of coatings. For example, [PERSON] et al. [17] used isophorone diisocyanate as the core material to prepare and characterize microcapsules, verifying their self-healing effect on coatings. [PERSON] et al. [18] prepared microcapsules with ethylenediamine as the core material and epoxy resin as the wall material, studied the effects of preparation factors on the morphology of the microcapsules, and tested the environmental resistance of the microcapsules. [PERSON] et al. [19] prepared fully aliphatic polyamide microcapsules using ethylenediamine and sebacoyl chloride, analyzing the effects of key process parameters on the microcapsules during polymerization. [PERSON] et al. [20] prepared double-layer self-healing microcapsules with isocyanate as the core material and polyurea and melamine resin as the shell materials, studied the mechanical properties of the microcapsules, and characterized the self-healing properties of the microcapsule coating using optical microscopy. Additionally, [PERSON] et al. [21] prepared double-layer microcapsules using phenolic resin and polyurethane as the shell materials and isophorone diisocyanate as the core material, with comprehensive characterization of the physical and chemical properties of the microcapsules. The above research indicates that the core materials currently used for preparing microcapsules are mainly limited to isocyanates and ethylenediamines, while the wall materials are mostly polyurethane and melamine resin types. As healing agents for microcapsules, ethylenediamine, and isocyanate compounds provide excellent self-healing properties; however, their toxicity and volatility may pose potential risks to the environment and to personnel handling these materials [22; 23]. As shell materials for microcapsules, polyurethane, and melamine resins can provide good mechanical properties, but they have shortcomings in UV resistance and corrosion resistance [24].