NMR Imaging of Elastomeric Materials

Abstract

NMR imaging has been applied to some elastomeric materials of industrial and military interest. The T2 spin-spin relaxation times of common elastomers, particularly after filling and curling, are sufficiently short that spin-echo sequences at submillisecond echo times cannot produce T2-independent images. The sensitivity to T2 potentially makes spin echo imaging a good probe of elastomer blend composition, as demonstrated for a series of filled and cured cis-polybutadiene, styrene-butadiene rubber blends. The technique can be used to distinguish good and bad carbon black dispersion in actual tire tread samples. The configuration of polyester tire cord, voids, rubber layer boundaries, apparent migration of additives, and other inhomogeneities can be detected in end-product tire samples. NMR images have been obtained for four porous glass disks of different porosities as models of materials such as oil cores. The mottled appearance often seen for such images is attributed largely to insufficient signal-to-noise ratio, and not pore structures. Comparison of spin- echo and gradient-echo images demonstrates the defect-magnification effect of the gradient-echo.

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Document Details

Document Type
Technical Report
Publication Date
Nov 30, 1990
Accession Number
ADA230299

Entities

People

  • E. W. Wooten
  • Richard A. Komoroski
  • Subhendra N. Sarkar

Organizations

  • University of Arkansas for Medical Sciences

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Boundaries
  • Chemistry
  • Composite Materials
  • Elastomers
  • Imaging Techniques
  • Magnetic Resonance
  • Materials Laboratories
  • Materials Science
  • Nuclear Magnetic Resonance
  • Polymers
  • Porosity
  • Porous Materials
  • Quantum Properties
  • Relaxation Time
  • Resonance
  • Rubber
  • Three Dimensional

Readers

  • Medical Imaging.
  • Polymer Science and Engineering.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.