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Conformational energy calculations on the crystalline state of mesogenic polyesters

✍ Scribed by Roberto Napolitano; Beniamino Pirozzi; Angela Tuzi

Publisher: Elsevier Science
Year: 1988
Tongue: English
Weight: 404 KB
Volume: 24
Category: Article
ISSN: 0014-3057
DOI: 10.1016/0014-3057(88)90135-8

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✦ Synopsis

Abstraet---Conformational energy calculations have been performed on the isolated chain in the crystalline state of polyesters of the series having formula [-1,4-C6H4C(CH3)=N-N--C(CH3)-I,4-C6HaOOC(CH2)n_ 2COO-]x, with 8 ~< n ~< 12, showing nematic mesophases with odd-even effects. Maps of the conformational energy as a function of pairs of torsion angles in the flexible part of the chain show a number of low energy regions. Starting from the minima of the maps, the energy has been optimized with respect to all the torsion and bond angles in the flexible part of the chains. Only a few conformations resulting from the energy minimizations are compatible with the experimental c axes for each polymer of the series.

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