ISSN:
0268-2605
Keywords:
organophosphazenes
;
liquid crystals
;
phase transition
;
Chemistry
;
Industrial Chemistry and Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Organophosphazenes with a similar mesogenic moiety were prepared and their mesogenicity was studied by differential scanning calorinetry (DSC) measurements and polarizing microsope observations. In cyclotriphosphazenes with alk-oxybiphenyl and Schiff base moieties, mesomorphic phase transitions were observed, but no mesomorphic phase was observed for the corresponding cyclotetraphosphazenes. In polyphos-phazenes with an alkoxybiphenyl moiety, no mesomorphic phase was observed. The molecular structure of cyclotriphosphazenes facilitated the formation of a mesomorphic layer structure; in contrast, the formation of a mesomorphic layer structure did not occur in cyclotetraphosphazenes and polyphosphazenes, even though they bore a similar mesogenic moiety. Moreover, in cyclotriphosphazenes with an optically active alkoxybiphenyl group, a smectic C* phase was observed. The spontaneous polarization of the compound was -190 μ C m-2 at 436 K in 25 μ in cell using the triangular-wave method. © 1998 John Wiley & Sons, Ltd.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
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