Journal of Materials Science

, Volume 39, Issue 5, pp 1703–1710 | Cite as

Microcapsule induced toughening in a self-healing polymer composite

  • E. N. Brown
  • S. R. White
  • N. R. Sottos


Microencapsulated dicyclopentadiene (DCPD) healing agent and Grubbs' Ru catalyst are incorporated into an epoxy matrix to produce a polymer composite capable of self-healing. The fracture toughness and healing efficiency of this composite are measured using a tapered double-cantilever beam (TDCB) specimen. Both the virgin and healed fracture toughness depend strongly on the size and concentration of microcapsules added to the epoxy. Fracture of the neat epoxy is brittle, exhibiting a mirror fracture surface. Addition of DCPD-filled urea-formaldehyde (UF) microcapsules yields up to 127% increase in fracture toughness and induces a change in the fracture plane morphology to hackle markings. The fracture toughness of epoxy with embedded microcapsules is much greater than epoxy samples with similar concentrations of silica microspheres or solid UF polymer particles. The increased toughening associated with fluid-filled microcapsules is attributed to increased hackle markings as well as subsurface microcracking not observed for solid particle fillers. Overall the embedded microcapsules provide two independent effects: the increase in virgin fracture toughness from general toughening and the ability to self-heal the virgin fracture event.


Epoxy Fracture Toughness DCPD Neat Epoxy Silica Microsphere 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • E. N. Brown
    • 1
    • 2
  • S. R. White
    • 3
  • N. R. Sottos
    • 1
  1. 1.Department of Theoretical and Applied Mechanics and the Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaUSA;
  2. 2.Los Alamos National Laboratory, MS-E544Los AlamosUSA
  3. 3.Department of Aerospace Engineering and the Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaUSA

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