Facile fabrication of self-healing silicone-based poly(urea-thiourea)/tannic acid composite for anti-biofouling

•A novel composite of silicone-based poly(urea-thiourea) and tannic acid is prepared by a facile method.•The composite presents a tough and highly stretchable performance.•The composite exhibits a fast self-healing property at room temperature in both air and artificial sea water.•The coating based on the composite shows a strong adhesion strength to substrates.•The coating exhibits a good antibacterial property and favorable anti-diatom performance.