Molecular orientation in quenched channel flow of a flow aligning main chain thermotropic liquid crystalline polymer

N. Vaish, D. K. Cinader, W. R. Burghardt*, W. Zhou, J. A. Kornfield

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

We report measurements of molecular orientation in solid specimens of a main-chain thermotropic liquid crystalline polymer (LCP) that were quenched from mixed shear-extensional channel flows. The polymer under investigation is a random copolyether with mesogens separated by flexible hydrocarbon spacers. This polymer is known to exhibit 'flow aligning' dynamics under slow shear flow. Experiments were designed to preserve the molecular orientation state, representative of steady, isothermal channel flow in the solid samples, so that comparisons could be made against in situ channel flow measurements on other main chain thermotropes without flexible spacers, including a commercial fully aromatic copolyster. In the flow aligning material, little change in orientation was found in slit-contraction flows, and only modest drops in orientation were found in slit-expansion flow. This contrasts strongly with data on commercial LCPs, suggesting that these materials may be of the 'tumbling' type.

Original languageEnglish (US)
Pages (from-to)10147-10153
Number of pages7
JournalPolymer
Volume42
Issue number26
DOIs
StatePublished - Sep 26 2001

Keywords

  • Director tumbling
  • Injection molding
  • Liquid crystalline polymer

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Molecular orientation in quenched channel flow of a flow aligning main chain thermotropic liquid crystalline polymer'. Together they form a unique fingerprint.

Cite this