Integration of multistructured microcapsules with self-healing and antimicrobial properties into polymer coatings for enhanced metal surface protection

To address the issue of corrosion in natural gas pipelines under complex environments, traditional protective methods such as corrosion inhibitors, antimicrobial agents, and coatings often fail to provide long-term protection. This study developed a high-performance anticorrosive coating with antibacterial and self-healing properties. Using urea-formaldehyde prepolymer (PUF) as the wall material and clove oil (Co) and epoxy resin (EP) as the core materials, multi-scale hierarchical microcapsules were synthesized via in-situ polymerization and incorporated into a quaternized epoxy resin matrix(EP-QAC). Compared with the pure EP coating, the Co/EP@PUF/EP-QAC coating maintains an impedance modulus of 1.37 × 10⁷ Ω·cm² at |Z|_0.01 Hz after 16 days of immersion. It also demonstrates excellent self-healing performance in immersion tests conducted over 1–5 days following scratch treatment. Furthermore, antibacterial testing reveals that the Co/EP@PUF/EP-QAC coating effectively inhibits the growth of sulfate-reducing bacteria (SRB), highlighting the synergistic enhancement of antibacterial properties achieved through the incorporation of Co/EP@PUF microcapsules and the quaternary ammonium-modified epoxy matrix. This study offers a promising strategy for the long-term protection of metal surfaces in harsh industrial environments.