Hierarchical Structure in Polymeric Solids and Its Influence on Properties.

Abstract

Of the variety of avenues arising from our preceding investigations of Professor Percec's (Cleveland) specially synthetized mesogenic polyethenes, currently we pursued the aspect of non-equilibrium liquid crystal deficiency ( degree of (non-equilibrium) liquid crystallinity ) and its perfectioning on heat treatments. We established and compared the effect of heat treatments both when annealed while in the liquid crystalline and in the crystalline solid state with numerous implications arising. We investigated effects related to non-equilibrium liquid crystal deficiency as a function of chain flexibility and molecular weight (M). We observed, amongst others, that increased flexibility reduces this deficiency and promotes perfectioning when such deficiency is present, while decreasing flexibility and increasing M has the opposite effect with the outcome that variability of degree of liquid crystallinity , as normally observed, is most pronounced at intermediate flexibilities and molecular weights.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1988
Accession Number
ADA193538

Entities

People

  • A. Keller

Organizations

  • University of Bristol

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Crystals
  • Diffraction
  • Heat Treatment
  • Liquid Crystals
  • Materials
  • Molecular Weight
  • Molecules
  • Orientation (Direction)
  • Phase Transformations
  • Polymers
  • Raman Spectra
  • Recognition
  • Scattering
  • Spectra
  • Transition Temperature
  • X Ray Scattering
  • X Rays

Readers

  • Plasma Physics.
  • Polymer Science and Technology
  • Systems Analysis and Design