Synthesis and characterization of the beta-diketone based side chain liquid crystalline random copolyphenylsilsesquioxane and its metal complex

Authors
Citation
Yz. Wan et al., Synthesis and characterization of the beta-diketone based side chain liquid crystalline random copolyphenylsilsesquioxane and its metal complex, MOLEC CRYST, 369, 2001, pp. 117-127
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Volume
369
Year of publication
2001
Pages
117 - 127
Database
ISI
SICI code
Abstract
The attachment of low molecular weight beta -diketone compound to random co polyphenylhydrosilsesquioxane (abbr. as Ph-T) backbone gave rise to the for mation of beta -diketone based side chain liquid crystalline copolyphenylsi lsesquioxane (abbr. as Ph-DK). Its copper complexes (abbr. as Ph-DK-Cu) wer e prepared following a heterogeneous reaction procedure. The structures of the Ph-DK and their copper complexes were well characterized by IR, NMR and GPC. The DSC heating curves of the Ph-DK-Cu show three endothermic transit ions. The first transitions are from crystalline state to liquid crystallin e state (I), the second transitions are from liquid crystalline state (I) t o liquid crystalline state (II), and the third transitions are from liquid crystalline state to the isotropic liquid. The Ph-DK-Cu are thermotropic li quid crystalline polymers. Their clearing temperature and mesophase range D eltaT are lower than those of the corresponding Cu-coordinated beta -diketo ne based copolymethylsilsesquioxane liquid crystalline polymers. The influe nce of the content of the Cu2+ on the Ph-DK-Cu has been discussed. The chen -deal incorporation of metal ion into polysilsesquioxane molecule can chang e the liquid crystal molecular arrangement and the transition temperature.