Crack propagation self-healing polymers

Figure 5.45. Schematic illustrating the mode of action of self-healing polymers through embedded healing-agent microcapsules that are activated by a propagating crack. Also shown is a polymeric microcapsule following rupture. Reproduced with permission from White, S. R. Sottos, N. R. Geubelle, R H. Moore, J. S. Kessler, M. R. Sriram, S. R. Brown, E. N. Viswanathan, S. Nature, 2001, 409, 794. Copyright 2001 Macmillan Magazines.

Fig. 1. Original microencapsulation-based self-healing system. Microencapsulated dicy-clopentadiene is embedded in an epoxy resin containing Grubbs catalyst which is capable of polymerizing the dicyclopentadiene. A propagating crack ruptures the microcapsules causing DCPD to be released into the crack plane where it comes in contact with and reacts with catalyst to form a polymer that bonds the crack hices and restores structural continuity.

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