Accession Number:

ADA193537

Title:

Hierarchical Structure in Polymeric Solids and Its Influence on Properties.

Descriptive Note:

Research rept. no. 5, Apr-Sep 87,

Corporate Author:

BRISTOL UNIV (ENGLAND)

Personal Author(s):

• Keller, A.

Report Date:

1987-09-01

Pagination or Media Count:

24.0

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.

Descriptors:

• *POLYMERS
• *SOLIDS
• *ETHERS
• CRYSTALS
• HIERARCHIES
• ISOTROPISM
• LIQUID CRYSTALS
• LIQUIDS
• MODELS
• PHASE
• POLYETHERS

Subject Categories:

• Organic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE