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