Dynamic covalent-crosslinked furan-modified CaCu3Ti4O12/polyurethane composite-based triboelectric nanogenerator and its application in self-powered cathodic protection

Providing a green and sustainable cathodic protection method for metal surfaces is the key to increasing the service life of equipment. Herein, furan-modified CaCu₃Ti₄O₁₂ (F-CCTO) and polyurethane with maleimide group as side group (MPU) were synthesized to prepare the high-performance dynamic covalent-crosslinked F-CCTO/MPU (FP) composites. And then the FP composites were further used to construct a triboelectric nanogenerator (FP-TENG) for Q235 steel cathodic protection. The results show that at 1-wt% F-CCTO content, the tensile strength and T_10% of the FP composite increased by 83.3% and 30 °C, respectively, compared with those of pure MPU. In addition, short-circuit current (I_sc), open-circuit voltage (V_oc), and peak power density of the FP-TENG were 4.6 μA, 100 V, and 3.3 Wm⁻², respectively. Notably, the mechanical and electrical output properties of the reprocessed FP composites obtained using the inverse Diels–Alder (DA) reaction are almost unchanged compared to the original FP composites. Electrochemical experimental results confirmed that the Q235 steel connected to the FP-TENG cathodic protection system exhibits excellent corrosion resistance. The corrosion potential of Q235 steel was reduced by about 110 mV, and in addition, the corrosion prevention mechanism of self-powered cathodic protection of metal surfaces was discussed.