Effect of a fluorine lateral moiety on the liquid crystallinity of wholly aromatic polyester-amides

Si Xue Cheng, Tai-Shung Chung*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

We have identified the effect of a fluorine lateral moiety on the liquid crystallinity of wholly aromatic polyester-amides, The evolution of liquid crystal texture for two reaction systems, p-acetoxybenzoic acid (ABA)/acetoxy acetanilide (AAA)/3-fluorophthalic acid (FPA) and ABA/AAA/phthalic acid (PA), were examined and compared by in situ polymerizations under a polarizing microscope with a heating-stage. The fluorine lateral moiety was found to have an adverse effect on the liquid crystallinity. The system containing FPA needs higher critical ABA content (the rigid and straight monomer) to form liquid crystallinity than the system containing PA. In addition, the LC phase emerges faster in the ABA/AAA/PA system than in the ABA/AAA/FPA system during polymerizations. Amorphous phase reappears in the later stage of thin film polymerizations for both systems if ABA content is in a particular range. However, the ABA/AAA/FPA system has a greater amorphous area than the ABA/AAA/PA system.

Original languageEnglish (US)
Pages (from-to)7433-7441
Number of pages9
JournalPolymer
Volume43
Issue number26
DOIs
StatePublished - Nov 21 2002

Keywords

  • Fluorine
  • Liquid crystalline polymer
  • Liquid crystallinity

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics

Cite this