To date, transparent polymeric elastomers with high mechanical toughness and excellent self-healing ability have shown attractive prospects in various fields. However, it is difficult to balance the trade-off between self-healing and mechanical performance, and it is even harder to get a transparent one. Herein, novel polyurea materials, which were cross-linked by rationally designed multi-strength hydrogen bonding interactions as well as covalent bonds, were developed. Covalent cross-links enabled high strength, while multi-strength hydrogen bonds as dynamic cross-links ensured elasticity, energy dissipation and rapid self-healing at room temperature. The designed polymer exhibited exceptional mechanical properties such as high elongation at break (over 1600%), notch-insensitive stretchability (800%), and high toughness of 12 500 J m⁻². Additionally, it was observed that the polymer could achieve up to 100% self-healing efficiency after 6 h without any external stimuli and an average transmittance of 92.8% at a film thickness of only 1.3 mm. After scratching, the film could still regain its transparency. Notably, this robust, transparent, stretchable, and self-healing elastomer can be employed as an optical protective coating against damage and will open a new avenue for next-generation sustainable optical-electrical and display screen devices.

中文翻译：

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一种高度可拉伸的，透明的，对缺口不敏感的自修复弹性体，用于涂料

迄今为止，具有高机械韧性和优异的自修复能力的透明聚合物弹性体已在各个领域中显示出诱人的前景。但是，很难在自我修复和机械性能之间进行权衡，甚至更难获得透明的。本文中，开发了通过合理设计的多强度氢键相互作用以及共价键交联的新型聚脲材料。共价交联键可实现高强度，而多强度氢键作为动态交联键可确保弹性，能量耗散和在室温下快速自愈。设计的聚合物表现出出色的机械性能，例如高断裂伸长率（超过1600％），对缺口不敏感的拉伸性（800％）和12500 J m的高韧性⁻²。另外，观察到该聚合物在6小时后可以实现高达100％的自愈效率，而没有任何外部刺激，并且在仅1.3mm的膜厚度下的平均透射率为92.8％。刮擦后，该膜仍可以恢复其透明度。值得注意的是，这种坚固，透明，可拉伸和自修复的弹性体可用作光学保护涂层，防止损坏，并将为下一代可持续的光电和显示屏设备开辟新的途径。