Liquid crystalline cellulose derivatives

Conference · Sat Jan 01 00:00:00 EST 1983 · J. Appl. Polym. Sci.: Appl. Polym. Symp.; (United States)

OSTI ID:6980365

Gray, D G

Following the observation that (hydroxypropyl)cellulose in water forms an ordered cholesteric liquid crystalline phase at high polymer concentrations, reports that many other cellulose derivatives in a wide variety of solvents also form liquid crystalline solutions have appeared in the scientific and patent literature. A tabulation of cellulose-based liquid crystalline systems is presented. The formation of the ordered phase is attributed to the limited flexibility of the cellulose chain. However, some cellulose derivatives form liquid crystalline phases only in specific solvents; concentrated solutions in other solvents remain isotropic. Other cellulose derivatives, such as (hydroxypropyl)cellulose, appear to form liquid crystalline solutions in any solvent that dissolves sufficiently high concentrations of the polymer. It has been suggested that the role of flexible side-chain substituents is to allow the main chains to achieve their equilibrium orientational order. The presence of many large substituents on the cellulose backbone also increases the effective chain radius and may change the chain conformation. The effect of side-chain structure on the properties of cellulose liquid crystalline phases is thus of interest. A series of esters of (hydroxypropyl)cellulose have been prepared. In addition to forming liquid crystalline solutions in organic solvents, these materials also were found to form cholesteric thermotropic phases in the absence of solvent. The thermotropic phases show spontaneous molecular orientation and cholesteric reflection. On heating, a transformation to the isotropic melt occurs. The liquid crystalline state of cellulose and its derivatives is thus widely observed. 42 references, 4 figures, 3 tables.

• Research Organization: McGill Univ., Montreal, Quebec
• OSTI ID: 6980365
• Report Number(s): CONF-8205234-Vol.1
• Journal Information: J. Appl. Polym. Sci.: Appl. Polym. Symp.; (United States), Conference: 9. cellulose conference, Syracuse, NY, USA, 24 May 1982
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
CELLULOSE
CONVERSION
CELLULOSE ESTERS
SYNTHESIS
LIQUID CRYSTALS
BY-PRODUCTS
MOLECULAR STRUCTURE
OPTICAL PROPERTIES
ORGANIC SOLVENTS
PHASE TRANSFORMATIONS
POLYMERS
QUANTITY RATIO
RHEOLOGY
CARBOHYDRATES
CRYSTALS
ESTERS
FLUIDS
LIQUIDS
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
POLYSACCHARIDES
SACCHARIDES
SOLVENTS
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