University of Illinois Urbana-Champaign

In situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene

Brown, Eric N.; Kessler, Michael R.; Sottos, Nancy R.; White, Scott R.

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https://hdl.handle.net/2142/281

Description

Title
In situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene
Author(s)
  • Brown, Eric N.
  • Kessler, Michael R.
  • Sottos, Nancy R.
  • White, Scott R.
Issue Date
2003-02
Keyword(s)
  • smart materials
  • experimental solid mechanics
  • fracture
  • materials processing
  • micromechanics
Abstract
Microencapsulated healing agents that possess adequate strength, long shelf-life, and excellent bonding to the host material are required for self-healing materials. Ureaformaldehyde microcapsules containing dicyclopentadiene were prepared by in situ polymerization in an oil-in-water emulsion that meet these requirements for self-healing epoxy. Microcapsules of 10-1000 µm in diameter were produced by appropriate selection of agitation rate in the range of 200-2000 rpm. A linear relation exists between log(mean diameter) and log(agitation rate). Surface morphology and shell wall thickness were investigated by optical and electron microscopy. Microcapsules are composed of a smooth 160-220 nm inner membrane and a rough, porous outer surface of agglomerated urea-formaldehyde nanoparticles. Surface morphology is influenced by pH of the reacting emulsion and interfacial surface area at the core-water interface. High yields (80-90%) of a free flowing powder of spherical microcapsules were produced with a fill content of 83-92 wt% as determined by CHN analysis.
Publisher
Department of Theoretical and Applied Mechanics (UIUC)
Series/Report Name or Number
TAM Reports 1014
ISSN
0073-5264
Type of Resource
text
Language
en
Permalink
http://hdl.handle.net/2142/281

Owning Collections

Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.