Cordier Philippe, Tournilhac François, Soulié-Ziakovic Corinne, Leibler Ludwik
Matière Molle et Chimie, UMR 7167 CNRS-ESPCI, Ecole Supérieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75005 Paris, France.
Nature. 2008 Feb 21;451(7181):977-80. doi: 10.1038/nature06669.
Rubbers exhibit enormous extensibility up to several hundred per cent, compared with a few per cent for ordinary solids, and have the ability to recover their original shape and dimensions on release of stress. Rubber elasticity is a property of macromolecules that are either covalently cross-linked or connected in a network by physical associations such as small glassy or crystalline domains, ionic aggregates or multiple hydrogen bonds. Covalent cross-links or strong physical associations prevent flow and creep. Here we design and synthesize molecules that associate together to form both chains and cross-links via hydrogen bonds. The system shows recoverable extensibility up to several hundred per cent and little creep under load. In striking contrast to conventional cross-linked or thermoreversible rubbers made of macromolecules, these systems, when broken or cut, can be simply repaired by bringing together fractured surfaces to self-heal at room temperature. Repaired samples recuperate their enormous extensibility. The process of breaking and healing can be repeated many times. These materials can be easily processed, re-used and recycled. Their unique self-repairing properties, the simplicity of their synthesis, their availability from renewable resources and the low cost of raw ingredients (fatty acids and urea) bode well for future applications.
与普通固体仅有百分之几的伸长率相比，橡胶具有高达百分之几百的巨大伸长率，并且在应力释放后能够恢复其原始形状和尺寸。橡胶弹性是大分子的一种特性，这些大分子要么通过共价交联，要么通过诸如小玻璃态或晶态区域、离子聚集体或多个氢键等物理缔合在网络中连接。共价交联或强物理缔合可防止流动和蠕变。在此，我们设计并合成了通过氢键相互缔合形成链和交联的分子。该体系显示出高达百分之几百的可恢复伸长率，并且在负载下几乎没有蠕变。与由大分子制成的传统交联或热可逆橡胶形成鲜明对比的是，这些体系在断裂或切割时，只需将断裂面合拢在室温下即可自行愈合。修复后的样品恢复了其巨大的伸长率。断裂和愈合过程可以重复多次。这些材料易于加工、再利用和回收。它们独特的自修复特性、合成的简便性、可再生资源的可得性以及原料（脂肪酸和尿素）的低成本，预示着其未来良好的应用前景。
