A Photothermal Self-Healing Polyacrylate Gel Coating with Oxime–Carbamate Dynamic Bonds for De-Icing and Surface Protection

The development of protective coatings that integrate self-healing and environmental tolerance is vital for extending substrate lifespan. In this study, a multifunctional hydrogel composite coating is developed based on a waterborne polyacrylate dynamic covalent network containing oxime–carbamate bonds. The functional monomer MEOC, which contains an oxime–carbamate dynamic bond, was synthesized and incorporated into the waterborne polyacrylate matrix to form a hydrogel network (OC-PA) with intrinsic self-healing capability. Prussian blue (PB) and nano-SiO2 were incorporated to form a photothermal functional layer, imparting hydrophobicity and converting light into heat for de-icing, while also activating dynamic bond rearrangement within the substrate. When the MEOC content was 7 wt% and the PB content was 2 wt%, the coating temperature rose to 110 °C within 2 min under 0.6 W/cm2 irradiation, and the scratch healed within 5 min. After 1 h of fracture repair, the tensile strength reached 6.68 MPa, with a repair rate as high as 92.91%, and de-icing time was reduced from 343 s to 183 s. The coating achieved a water contact angle >100°. At −20 °C, the icing delay time increased by 215%. The hydrogel coating also exhibited excellent abrasion resistance, chemical stability, UV aging resistance, and anti-fouling properties, offering a durable solution for demanding environments.