Hierarchical Structure in Polymeric Solids and Its Influence on Properties.

Abstract

Work was again centered on the family of mesogen polyethers (synthetized by Professor Percec, Cleveland) serving as model substances for the exploration of polymeric structure hierarchy in polymers capable of displaying isotropic liquid crystal and crystalline phases in one and the same material. Amongst others an unexpected feature was recognized and then explored in some depth. This is the existence of a heat treatment dependent non-equilibrium liquid crystal deficiency manifest in lowered temperatures and heats of isotropization, with parallel manifestations of an optically visible microtexture as defined by networks of disinclinations. In addition to many forward looking consequences to be exploited the above findings enabled a quantification of the 'degree of liquid crystallinity', we maintain a significant parameter for the characterization of the pertinent materials.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1987
Accession Number
ADA193537

Entities

People

  • A. Keller

Organizations

  • University of Bristol

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alkanes
  • Amorphous Materials
  • Copolymers
  • Crystallization
  • Crystals
  • Frequency
  • Glass Transition Temperature
  • Heat Energy
  • Heat Treatment
  • Liquid Crystals
  • Materials
  • Mechanical Properties
  • Melting
  • Phase Diagrams
  • Phase Transformations
  • Transition Temperature
  • Transitions

Readers

  • Materials Science and Engineering.
  • Polymer Science and Technology
  • Theoretical Analysis.