Infrared-Assisted Healing and Corrosion Protection of Aromatic Thermosetting Copolyester Vitrimer Coatings in Various pH Environments

Traditional polymer coatings face significant challenges, including degradation from environmental exposure, mechanical damage, and limited reprocessability, raising concerns about long-term durability and environmental impact. In this study, we explore the potential of aromatic thermosetting copolyester (ATSP), a functional vitrimer, as an advanced self-healing and corrosion-resistant coating for carbon steel. ATSP is known for its high-performance properties, dynamic bond exchange capability, and strong adhesion to metal surfaces. We conducted a comprehensive evaluation of ATSP-coated carbon steel samples exposed to aggressive environments, including saline (3.5 wt % NaCl), acidic (1 M H2SO4), and basic (6 M KOH) conditions. Electrochemical tests such as polarization, contact angle measurements, and electrochemical impedance spectroscopy (EIS) were used to assess the corrosion resistance and durability of the ATSP coating. In addition, we investigated the self-healing properties of the ATSP coating using infrared (IR) heating after samples were scratched and exposed to corrosive environments. The results showed significant healing after the first IR cycle, with incremental improvements after the second, particularly for deeper scratches. Molecular dynamics (MD) simulations further demonstrated ATSP’s ability to self-repair through dynamic bond exchange reactions at the atomic level, with the healed polymer regaining 80% of its original mechanical properties.