Back to Search Start Over

Synthesis and Characterization of a Novel Liquid Crystalline Polymer Showing a Nematic Columnar to Nematic Discotic Phase Transition

Authors :
Kouwer, P. H. J.
Jager, W. F.
Mijs, W. J.
Picken, S. J.
Source :
Macromolecules; June 13, 2000, Vol. 33 Issue: 12 p4336-4342, 7p
Publication Year :
2000

Abstract

A novel liquid crystalline polyacrylate, exhibiting a nematic columnar and a nematic discotic phase, the latter not found in any polymer previously, has been synthesized using a polymer analogous reaction, substituting the discotic mesogens on a reactive polymer. The highly flexible concept of the polymer analogous reaction enables us to introduce structural variations and to create and control molecular architectures. The mesophases of polymer <BO>1</BO>, bearing the pentakis(methylphenylethynyl)benzene mesogen via a flexible undecanoxy spacer, as well as its low molar weight homologue <BO>2</BO>, were fully characterized by optical polarizing microscopy, differential scanning calorimetry and powder X-ray diffraction. The thermal behavior of both compounds is qualitatively similar. Both materials exhibit a nematic discotic phase (N<INF>D</INF>) at higher temperatures, which is unique for the polymer, as this phase has only been observed in low molar mass materials so far. At lower temperatures <BO>2</BO> crystallizes, whereas <BO>1</BO> undergoes a transition into the nematic columnar phase (N<INF>col</INF>).

Details

Language :
English
ISSN :
00249297 and 15205835
Volume :
33
Issue :
12
Database :
Supplemental Index
Journal :
Macromolecules
Publication Type :
Periodical
Accession number :
ejs1149051