Multiple dynamic bonds interactions toward rapidly self-healing, photothermal-responsive rosin-based elastomers

Despite the significant progress in the development of self-healing polymers with photothermal-responsive, it is still a challenge to balance the photothermal conversion efficiency and the dispersion of the photothermal agent in the material. To address this issue, we introduced rosin, Cu2+, and adipic dihydrazide, which can form high-density hydrogen bonds, into the polymer network, and developed a self-healing, photothermal-responsive rosin-based elastomers through the strategy of “building up strength from weakness”. The synergistic reinforcement of high-density hydrogen and metal−ligand bonds significantly improved the mechanical properties of the elastomers (tensile strength of 27.4 ± 0.4 MPa and toughness up to 100.3 ± 4.0 MJ m−3). Importantly, the introduction of Cu2+ provided the elastomer with a coordination bond to generate a photothermal effect to promote self-healing. The elastomer reached 121.6 °C at 20 s under near-infrared (NIR) light irradiation, and the outstanding photothermal conversion ability enabled the elastomer to realize fast and highly efficient photo-responsive healing (scratches could be completely healed in 40 s of NIR light irradiation). Furthermore, it was used as a photothermal self-healing anticorrosion coating, showing excellent corrosion resistance. Meanwhile, the designed photo-actuator exhibits fast and excellent photo-activation performance under NIR light irradiation. This work provides a new strategy for the application of photothermal-responsive sustainable biobased elastomers in smart anticorrosion coatings and flexible electronics.