Poly(urea-urethane) Elastomers Showing Autonomous Healing at Room Temperature

Abstract

Scratches on surfaces caused by abrasion induce the deterioration of the mechanical and optical properties of materials used in wearable electronics, soft robotics, optical lenses, and flexible displays. Ideally, these materials should be able to be autonomously repaired at room temperature without external stimuli. Herein, we report a series of poly(urea-urethane) transparent elastomers containing reversible disulfide and hydrogen bonds with the ability to heal at room temperature. The elastomers display a healing efficiency as high as 95% of mechanical properties, a high relative light transmittance (∼100%), and a complete recovery of light transmittance at 30 °C. The mechanical properties, optical transparency, and self-healing of the light transmittance of the elastomers could be tuned by the molecular design of their soft and dynamic hard segments. This study paves the way for exploring self-healing materials in structures that are difficult to access and for which autonomous healing without external stimuli is suitable.

Microscopic Mechanisms of Self-Healing in Polymers Revealed by Molecular Simulations and Machine Learning

“…There are a variety of methods for preparing self-healing polymers, among which the construction of reversible bonds or interactions in polymers is one of the most relevant. − For instance, hydrogen bonds, ,,− reversible covalent bonds, ,, metal–ligand coordination, − and ionic interactions , are introduced into polymers to achieve the self-healing ability. Among them, hydrogen-bonded self-healing polymers have attracted much attention due to the simple preparation process and the ease of industrial production. , …”