The Effect of Complex Emulsifier on the Structure of Tung Oil and Phenolic Amides Containing Microcapsules and Its Anti-Fouling and Anti-Corrosion Performances

In this study, the urea-formaldehyde (UF)-tung oil solution of phenolic amide (PA) microcapsules to realize anti-fouling and anti-corrosion integration was synthesized by the in situ polymerization method. The compounds and structures were optimized by investigating six kinds of different emulsifiers. The results showed that high-core-content and narrow-particle-size-distribution microcapsules could be synthesized with sodium dodecyl benzene sulfonate (SDBS)/polyvinyl alcohol (PVA), and the core content of the microcapsules was 75 wt% at microcapsule sizes from 24.07 to 71.33 µm. The results of self-healing coatings showed that when the content of microcapsules in the coating exceeded 10 wt%, the healing agent released from the scratched surface could cover the naked metal effectively, which could pass a 7 day neutral salt spray test without rust at the scratched area. A sufficient dose anti-fouling agent can be provided to prevent diatoms and mussels from adhering. The present work shows that the complex emulsifier can better control the particle size distribution and microstructure of the microcapsules, and the admixture of the microcapsules into the resin epoxy coating can realize excellent anti-corrosion and anti-fouling functions.