Self-passivation/self-delivery/self-healing anticorrosion polymer coating for marine applications

Area of Science:

• Materials Science
• Corrosion Engineering
• Polymer Chemistry

Background:

• Steel corrosion in marine environments severely limits the lifespan of structures.
• Conventional polymeric coatings struggle to prevent seawater penetration due to their molecular structure.
• There is a need for advanced anticorrosion technologies that can actively combat degradation.

Purpose of the Study:

• To develop a novel hyperbranched polyurethane-based coating with dopamine (DOPA) for enhanced marine corrosion protection.
• To investigate the self-passivation, self-delivery, and self-healing capabilities imparted by the DOPA component.
• To evaluate the effectiveness of this dynamic active anticorrosion strategy compared to traditional passive methods.

Main Methods:

• Synthesis of a hyperbranched polyurethane coating functionalized with terminal dopamine (DOPA).
• Incorporation of DOPA to capture released iron ions and form protective complexes.
• Testing the coating's performance on tinplate (steel model) in a marine environment.
• Quantification of corrosion using electrochemical techniques (corrosion current and rate).

Main Results:

• The DOPA-functionalized coating demonstrated remarkable self-passivation, self-delivery, and self-healing properties.
• Corrosion of the tinplate model was reduced to an unprecedented low level (corrosion current = 1 × 10⁻⁹ A cm⁻², corrosion rate = 1 × 10⁻⁵ mm year⁻¹).
• The developed coating effectively utilizes seawater, transforming it from a corrosive agent to a beneficial factor.

Conclusions:

• The novel hyperbranched polyurethane coating with DOPA offers a dynamic active anticorrosion strategy superior to static passive approaches.
• This innovative coating technology significantly enhances the durability of steel in harsh marine environments.
• The findings pave the way for developing long-lasting marine coatings with self-healing functionalities.