ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Several series of thermotropic copolyesters with different spacers, containing the moieties of 1,4-butanediol (4a or 4b), 1,6-hexanediol (6a or 6b), bisphenol-A (10a), bisphenol-S (10b) or a telechelic polysulfone (12a or 12b) were synthesized. The mesomorphic properties of the resulting copolyesters were examined by visual observation of stir-opalescence and birefringence under a polarizing microscope. Copolyesters 4a, 4b, 6a or 6b with mole fractions of mesogenic units over a broad extent (≥0,2) being thermotropic within wide mesomorphic temperature ranges, regardless of the spacers based on 1,4-butanediol or 1,6-hexanediol, have microstructures of block sequence distribution and do not retain liquid-crystallinity if the mean lenghts of mesogenic segments are shorter than that of the triad with three phenyl rings. For the thermotropic copolyesters 10a, 10b, 12a or 12b the minimum mole fraction of mesogenic units needed is not higher than 0,10, despite of the different varieties and lengths of rigid spacers.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1988.021890902
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