A Self-repairing transparent film with reprocessable, ultra-high strength and outstanding elasticity based on interlocking hydrogen bonds and reversible topological networks

Achieving robust, high elasticity, transparency, self-repairing, reprocessability and durability simultaneously remains a huge challenge. In this work, we propose a simple strategy to prepare an ultra-high strength, outstanding elasticity, self-repairing and reprocessable poly (thiourethane-urea) (PTUU) film based on interlocking hydrogen bonds (IHBs) and reversible topological networks. The IHBs between its main chains make it have ultra-high tensile strength (61.6 MPa) and good scratch resistance. It is the highest tensile strength ever recorded for crosslinked self-repairing materials at medium temperature thus far. The synergistic effect of IHBs and topological networks makes it high elasticity and can repair more than 90 % of the mechanical strength. Rearrangement of reversible topology network at high temperature endows PTUU with reprocessability, and the mechanical strength remains more than 85 % after reprocessing for three times. In addition, PTUU films have high transmittance (96.6 %, 0.5 mm), low haze, high refractive index and excellent durability, which have broad application prospects in transparent protective materials, optical lenses, stretchable fibers, wearable electronic devices and other fields.