Experimental Mechanics

, Volume 46, Issue 6, pp 725–733 | Cite as

Mechanical Properties of Microcapsules Used in a Self-Healing Polymer

  • M. W. Keller
  • N. R. Sottos


The elastic modulus and failure behavior of poly(urea-formaldehyde) shelled microcapsules were determined through single-capsule compression tests. Capsules were tested both dry and immersed in a fluid isotonic with the encapsulent. The testing of capsules immersed in a fluid had little influence on mechanical behavior in the elastic regime. Elastic modulus of the capsule shell wall was extracted by comparison with a shell theory model for the compression of a fluid filled microcapsule. Average capsule shell wall modulus was 3.7 GPa, regardless of whether the capsule was tested immersed or dry. Microcapsule diameter was found to have a significant effect on failure strength, with smaller capsules sustaining higher loads before failure. Capsule size had no effect on the modulus value determined from comparison with theory.


Self-healing composite Microcapsule Compression Urea-formaldehyde Modulus Strength 


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Copyright information

© Society for Experimental Mechanics 2006

Authors and Affiliations

  1. 1.Department of Theoretical and Applied Mechanics and Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaUSA

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