Abstract
A range of mixed ether‐esters of cellulose was prepared from partially substituted ethylcellulose and methylcellulose. The 13C‐NMR analysis of ethylcellulose with a DS of 2.5 indicated that the hydroxyl groups at carbon six of anhydroglucose units were completely substituted. Acetylation of the ethylcellulose under different conditions yielded (acetyl) (ethyl) cellulose (AEC) samples with acetyl degree of substitution ranging from 0 to 0.5. Fully substituted (propionyl) (ethyl) cellulose (PEC) and (acetyl) (methyl) cellulose (AMC) were also prepared. Chiral nematic liquid crystals were formed in these mixed ester/ethers of cellulose in concentrated solutions of acidic solvents. The critical concentration for the phase separation of the cellulosic solutions depended on the nature of the substituent, the degree of substitution, and the solvent at a given temperature. Methylcellulose solutions in trifluoroacetic acid and dichloroacetic acid form chiral nematic liquid crystals with a left‐handed helicoidal structure. The acetylated methyl cellulose samples did not show the reversal of handedness with increasing acetyl content that was previously observed for the corresponding ethylcellulose samples. © 1994 John Wiley & Sons, Inc.
Original language | English (US) |
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Pages (from-to) | 889-896 |
Number of pages | 8 |
Journal | Journal of Polymer Science Part A: Polymer Chemistry |
Volume | 32 |
Issue number | 5 |
DOIs | |
State | Published - Apr 15 1994 |
Externally published | Yes |
Keywords
- chiral‐nematic phases, handedness of
- ethylcellulose, liquid crystalline esters of
- methylcellulose, liquid crystalline esters of
ASJC Scopus subject areas
- Polymers and Plastics
- Organic Chemistry
- Materials Chemistry