Phase behavior of cyclic siloxane-based liquid crystalline compounds
- Wright Patterson Air Force Base, Dayton, OH (United States)
- Univ. of Connecticut, Storrs, CT (United States)
- Univ. of North Carolina, Chapel Hill, NC (United States)
The phase behavior of 24 cyclic siloxane liquid crystalline compounds are compared with respect to spacer length, composition, ring size, and mesogenic phase behavior. Penta- and tetramethylhydrocyclosiloxane rings were modified by biphenyl- and/or cholesterol-based molecules. A strong dependence of ring size on thermal behavior was observed for the homopolymers. 4-membered rings seem to inhibit the formation of liquid crystalline phases for biphenyl-based mesogens. Clearing temperatures for this series followed the melting temperatures of the unattached mesogens. Cholesterol-based compounds exhibited glass transition temperatures which increased substantially with spacer group length. A tendency to layer pack for the cholesterol compound was observed as smectic-A phases were formed.
- OSTI ID:
- 141537
- Report Number(s):
- CONF-930304-; TRN: 93:003688-1217
- Resource Relation:
- Conference: 205. American Chemical Society national meeting, Denver, CO (United States), 28 Mar - 2 Apr 1993; Other Information: PBD: 1993; Related Information: Is Part Of 205th ACS national meeting; PB: 1951 p.
- Country of Publication:
- United States
- Language:
- English
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