ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The synthesis of the liquid-crystalline polysiloxanes, 4a, 4b, 5a, 5b with 2,7-disubstituted fluorene units and of the related liquid-crystalline model compounds 2 and 3 is reported. Polymers 4a, 4b, 5a, 5b were prepared from monomers 2 and 3, respectively, and poly(hydrogenmethyl-siloxane) (PHMS) in a polymer-analogous reaction. The liquid-crystalline properties of the polymers and the corresponding low-molecular-weight compounds 2 and 3 were characterized by differential scanning calorimetry (DSC) and polarizing microscopy. Both compounds 2 and 3 show a smectic A and a smectic E mesophase, and the resulting polysiloxanes also exhibit smectic A- and smectic E-like textures but no nematic phase. The clearing point of the polymers is on the average by 100°C higher than that found for the low-molecular-weight compounds.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1990.021911229
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