Accession Number:

ADA248306

Title:

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

Descriptive Note:

Corporate Author:

CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE

Personal Author(s):

Report Date:

1992-03-27

Pagination or Media Count:

28.0

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.

Subject Categories:

  • Physical Chemistry
  • Polymer Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE