Science 9 May 2014:
Vol. 344 no. 6184 pp. 620-623
DOI: 10.1126/science.1251135

标题:Restoration of Large Damage Volumes in Polymers
作者:S. R. White1等
The regenerative power of tissues and organs in biology has no analog in synthetic materials. Although self-healing of microscopic defects has been demonstrated, the regrowth of material lost through catastrophic damage requires a regenerative-like approach. We demonstrate a vascular synthetic system that restores mechanical performance in response to large-scale damage. Gap-filling scaffolds are created through a two-stage polymer chemistry that initially forms a shape-conforming dynamic gel but later polymerizes to a solid structural polymer with robust mechanical properties. Through the control of reaction kinetics and vascular delivery rate, we filled impacted regions that exceed 35 mm in diameter within 20 min and restored mechanical function within 3 hours. After restoration of impact damage, 62% of the total absorbed energy was recovered in comparison with that in initial impact tests.

Editor’s summary:
Self-Healing Larger Wounds

By loading a polymer with pockets of monomer, it is possible to heal small cracks in a sample through the polymerization of the monomer following the formation of a crack. However, large holes are much harder to repair. White et al. (p. 620; see the Perspective by Zhao and Arruda) developed a vascular-like repair system involving a dual-stage strategy to self-heal epoxy thermosets. After injecting a damaged site with precursors, a gel with reversible cross-links rapidly formed, so the material stayed in place that then solidified further upon cross-linking. The approach successfully patched holes larger than 3 centimeters in diameter.



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