- 福井工業大学研究紀要 Memoirs of Fukui University of Technology (ISSN:18844456)
- no.43, pp.284-292, 2013
Ethy1cellulose (EC) exhibits interesting behavior in the formation of liquid crystals. Early observations indicated that most cellulosics formed right-handed cholesteric structure. However, EC in chloroform and acetic acid (AA) solutions took left-handed cholesteric liquid crystals, whereas EC in dichloroacetic acid (DCA) solution had right-handed ones. In the present study, (phenylacetyl)ethylcellulose (PA-EC) was prepared by the reaction of phenylacetyl chloride with EC having a degree of ethyl substitution (DSEt) of 2.26 in N,N-dimethylacetamide solution using triethylamine as proton scavenger. Reactions were usually carried out at room temperature for one week, which provided a variety of phenylacetyl contents (degree of substitution of phenylacetyl (DSPa) = 0.02, 0.11, 0.32, and 0.43). The chloroform and AA solutions of PA-EC with DSPa = 0.32 displayed a right-handed cholesteric liquid crystalline phase, while the DCA solution showed a left-handed one.