Structural Rearrangements During Mesomorphic Phase Transitions in Poly(10-((4-Cyano-4' Biphenyl)oxy )Decanyl Vinyl Ether

Abstract

The side chain liquid crystalline poly 10-(4-CYANO-4'-BIPHENYL) oxydecanyl vinyl ether) exhibits two different smectic phase: at low temperature an ordered smectic E phase with orthorhombic intralayer packing of the mesogenic groups, and at high temperatures a common disordered smectic A phase. In both phases a doublelayered longitudinal packing of the macromolecular fragments with a thickness of 6.6 -7 nm and overlapping of the slightly tilted mesogenic groups is realized. During the phase transition from the smectic E to the smectic A a melting of the intralayered packing occurs which leads also to the slight changes of the thickness of the smectic layers as a result of the conformational disordering of the side chains. A smectic Alike structure could be freezed in the glassy state by quick cooling. The development of the ordered smectic E phase as a result of annealing at temperatures higher than Tg is a very slow process since it requires the formation of the ordered intralayered orthorhombic packing of mesogenic groups.

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Document Details

Document Type
Technical Report
Publication Date
Mar 27, 1992
Accession Number
ADA248306

Entities

People

  • Minah Lee
  • V. Tsukrut
  • Virgil Percec

Organizations

  • Case Western Reserve University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alkenes
  • Glass Transition Temperature
  • Heating
  • High Temperature
  • Liquid Crystals
  • Low Temperature
  • Macromolecules
  • Military Research
  • Periodic Variations
  • Phase Transformations
  • Polymers
  • Scattering
  • Smectic Phase
  • Transition Temperature
  • Transitions
  • X Ray Scattering
  • X Rays

Readers

  • Materials Science and Engineering.
  • Nanofabrication and Microfabrication.
  • Organic Chemistry