Fabrication of multifunctional coating with anti-corrosion, weather-resistance and self-healing for Q235 steel via soft-hard hybrid architecture

A persistent pursuit in marine materials science is the development of strong and tough efficient anti-corrosion coatings for metal protection. Unfortunately, coating was universally challenged to balance the hardness and flexibility. Herein, this paper proposed a “soft-hard” hybrid structural strategy to integrate these properties. The coating was fabricated by embedding “hard” epoxy resins (EP) into “soft” polyurethane (PU), wherein EP cured by 4′-(p-ethanediamine phenyl)-2,2′:6′,2″-terpyridine. Diels-Alder dynamic bond, hydroxy terminated polydimethylsiloxane and functionalized boron nitride were introduced into to impart self-healing properties, hydrophobic and anti-corrosion performance. Prepared coated sample (PUSi3FET3BN) had superior hydrophobicity (114°), flexibility (43 MJ⋅m −3 ) and corrosion resistance (5 × 10 7  Ω·cm 2 after 28 days immersion). Moreover, PUSi3FET3BN sample demonstrated excellent weathering resistance and self-healing, allowed damaged samples healed at 100 °C for 60 min. This ingenious strategy provides valuable insights for development of multifunctional coatings, especially for protecting equipment in extremely harsh environments.