Self-healing and thermoreversible rubber from supramolecular assembly.
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.
Cordier
Philippe
P
Matière Molle et Chimie, UMR 7167 CNRS-ESPCI, Ecole Supérieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75005 Paris, France.
Tournilhac
François
F
Soulié-Ziakovic
Corinne
C
Leibler
Ludwik
L
D003460:Crystallization; D004548:Elasticity; D005227:Fatty Acids / Q000737:chemistry; D006860:Hydrogen Bonding; D019563:Mechanics; D012212:Rheology; D012408:Rubber / Q000737:chemistry*; D013696:Temperature; D014508:Urea / Q000737:chemistry
D005227:Fatty Acids; D014508:Urea; D012408:Rubber