Cellulose 4-Phenylphenoxyacetate: Synthesis in Imidazolium Ionic Liquid and Thermal Properties Characterization

Abstract

Esterification of cellulose with 4-phenylphenoxy acetic acid (PPA) in 1-butyl-3-methlimidazolium chloride (BMIMCl) has been performed with the aim of preparing novel liquid crystalline cellulose derivative. Effect of reaction conditions, such as type of esterification reagents and ionic species, on the thermal properties and solubility of the polysaccharide derivatives has been investigated. As the result, cellulose 4-phenylphenoxyacetate (CPA) with the maximum degree of substitution (DS) of 1.17 was attained by using 1,3-diisopropylcarbodiimide as the esterification reagent and by applying 8 molar parts of PPA against 1 molar parts of hydroxyl groups in cellulose. The esterification reaction was performed at 100 °C for 72 h without basic catalyst. The CPA retained almost constant dynamic storage modulus up to 120 °C and showed the 10 % weight decrease at 285 °C, that was 57 °C higher than the original cellulose. On the other hand, within the range of DS attained, CPA did not form mesophase on heating or in the solution state in dimethylsulfoxide and N,N-dimethylacetamide.