Photo-responsive rapid self-healing polyurethane elastomer with anticorrosion and antibacterial functions

• Cu(HD) 2 acts as a photothermal agent and chain extender and promotes the self-healing process. • Efficient photothermal performance brings ideal self-healing performance to PU. • Multifunctional PU coating exhibits excellent antibacterial and anticorrosion properties. In this paper, polyurethane (PU) with polyethylene glycol as a soft segment and isophorone diisocyanate as a hard segment were designed and synthesized. Copper complex (Cu(HD) 2 ) was synthesized in PU preparation, bringing excellent self-healing, photothermal and antibacterial properties. The content of Cu 2+ accounted for less than 2 wt% of PU elastomer. Cu(HD) 2 acted as a chain extender and provided coordination bonds for elastomer to promote the self-healing process. Experiments showed that Cu(HD) 2 exhibited excellent photothermal properties in PU. The maximum temperature of the samples after 5 min irradiation under a sunlight simulator could reach 120 °C. The results of the self-healing experiment showed that mechanical properties of PU could be recovered by nearly 90%, and electrochemical protection performance could be recovered by nearly 100%. Antibacterial experiments proved that PU could release Cu 2+ , forming an antibacterial ring around PU. PU has excellent application in the field of anticorrosion and antibacterial coatings.