The influence of ionic liquid concentration on microcrystalline cellulose modification

• Published in: Carbohydrate polymer technologies and applications Vol. 3; p. 100211
• Main Authors: Kerche, Eduardo Fischer, Neves, Roberta Motta, Ornaghi, Heitor Luiz, Zattera, Ademir José, Schrekker, Henri Stephan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2022; Elsevier
• Subjects: Imidazolium ionic liquid; Microcrystalline cellulose; Surface treatment; Thermal degradation kinetics; Imidazolium ionic liquid; Thermal degradation kinetics; Microcrystalline cellulose; Surface treatment
• ISSN: 2666-8939; 2666-8939
• DOI: 10.1016/j.carpta.2022.100211

•Ionic liquid modified MCC.•The onset of the thermogravimetric curves decreased in the same value, independent of IL concentration.•Arrhenius’ parameters and MCC degradation mechanisms were not altered by IL.•IL did not affect the MCC crystallinity of ∼ 86%.
Ethanolic ionic liquid (IL) solutions, containing different 1-n-butyl-3-methylimidazolium chloride (C4MImCl) concentrations were used to modify the surface of commercial microcrystalline cellulose (MCC). The chosen ratios were: 4, 8, 16, and 32 wt.% of IL, in relation to the MCC mass. These treatments with IL did not affect the MCC morphology. FTIR analysis showed the characteristic bands of C4MImCl when the IL concentration was higher than 4 wt.%. XRD diffractograms show that the crystals may have been disrupted for IL concentrations above 4 wt.%. 1H NMR confirmed the formation of strong hydrogen bonds between C4MImCl and MCC, especially for MCC treated with 4 wt.% of IL. The functionalization using IL, regardless of the content, showed two DTG peaks, without altering the MCC Arrhenius’ parameters and degradation mechanisms. 4 wt.% of C4MImCl proved to be suitable for the MCC surface modification, improving thermal stability without detrimental effects on MCC morphology.
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