Self-Healing of Cracks in Epoxy Composites
To provide epoxy based composites with self-healing ability, two-component healing system consisting of urea-formaldehyde walled microcapsules containing epoxy (30~70µm in diameter) and CuBr2(2-MeIm)4 (the complex of CuBr2 and 2-methylimidazole) latent hardener was synthesized. When cracks were initiated or propagated in the composites, the neighbor micro-encapsulated epoxy would be damaged and released. As the latent hardener is soluble in epoxy, it can be well dispersed in epoxy composites during composites manufacturing, and hence activate the released epoxy wherever it is. As a result, repair of the cracked sites is completed through curing of the released epoxy. The present work indicated that the plain weave glass fabric laminates using the above self-healing epoxy as the matrix have been provided with self-healing capability.
Alan K.T. Lau, J. Lu, Vijay K. Varadan, F.K. Chang, J.P. Tu and P.M. Lam
T. Yin et al., "Self-Healing of Cracks in Epoxy Composites", Advanced Materials Research, Vols. 47-50, pp. 282-285, 2008