Degradable, Self-Healing, Humidity-Driven Poly(urethane-Urea) Film

Humidity-driven materials are widely used in actuators, soft robots, sensors, and other fields. The extensive use of these materials increases the demand for degradable, highly durable, and self-healing materials. However, the preparation of such ideal materials still faces serious challenges. Herein, a novel poly(urethane-urea) film material (PUU-DHA-Cu4) with synergetic quadruple dynamic bonds (acylhydrazone bonds, boron-oxygen bonds, coordination bonds, and hydrogen bonds) is developed. The prepared PUU-DHA-Cu4 film material exhibited a tensile strength of 23.2 MPa, an elongation at break of 1142 %, and a healing efficiency of 90.1 % after 48 h of self-healing at room temperature. Meanwhile, the reversibility of the boron-oxygen bond imparts degradability to the material. Finally, a humidity-driven poly(urethane-urea) material that not only has self-healing ability but can also be degraded easily was successfully developed. This work will make a valuable addition to the field of environment-friendly humidity-driven materials.