Blending of Cellulose and Chitosan in Alkyl Imidazolium Ionic Liquids

Abstract

The production of cellulose/chitosan blends in alkyl imidazolium ionic liquids (ILs) was studied in this work. Selected organic solvents, such as dimethyl sulfoxide, ethyl acetate, and diethyl ether, were used as cosolvents. The addition of cosolvents decreased the viscosity of cellulose/chitosan solutions in ILs and facilitated the dissolution of polysaccharides, thereby decreasing the E act and polymer aggregates sizes in the solutions. The cellulose/chitosan films were produced from the studied solutions. The presence of one of cosolvent and ILs in the blended films was confirmed by FTIR spectroscopy. The blended film is stronger than pure cellulose film, and the addition of cosolvents has an influence on its mechanical properties.

Multifilament cellulose/chitin blend yarn spun from ionic liquids

“…This general class of compounds is by this time used in many scientific and technical applications; these compounds are based on specific compositions of different cations and anions, which lead to a liquid state at room temperature, exhibit low viscosities, are often stable against thermal load and, most remarkably, show a considerable capability to interrupt strong H-bond interactions and are easily removable. Some ILs were found to be promising solvents for chitin and chitin/cellulose blends (John & Thomas, 2008;Kadokawa, 2013;Klemm et al, 2005) and have been used to prepare various chitin/cellulose and chitosan/cellulose blend materials like gels, foils, coatings and fibers with varying structures and for different applications (Bochek et al, 2012;Kadokawa, Hirohama, Mine, Kato, & Yamamoto, 2012;Kuzmina, Heinze, & Wawro, 2012;Ma, Hsiao, & Chu, 2011;Pillai et al, 2009;Shamsuri & Daik, 2015;Takegawa, Murakami, Kaneko, & Kadokawa, 2010) as well as nanofiber-reinforced materials thereof (Kadokawa, Endo, Hatanaka, & Yamamoto, 2015). However, up to now all applied ILs, e.g., [C2mim] + [Cl] − (1-ethyl-3-methylimidazolium-chloride), cannot simultaneously dissolve sufficient amounts of chitin and cellulose, often exhibit toxicity and corrosivity and are therefore not suitable for establishing a multifilament wet spinning process for the above-mentioned biopolymer blend/IL systems.…”

Green polymer electrolytes based on chitosan and 1-butyl-3-methylimidazolium acetate

“…Also, peak at 1550 cm -1 attributed to N-H bending of primary amide (-NH 2 ) is shifted to 1560 cm -1 . A high increase in the intensity has also been observed in this characteristic peak that may be also attributed to the asymmetric carboxylate anion, COO -stretching in the acetic acid [15] and also C=C imidazolium ring stretching in the imidazolium ring [3]. Sharp peak at 1322 cm -1 which probably belong to C-N stretching in imidazolium ring is shifted to 1334 cm -1 .…”

“…Peak at 1019 cm -1 is shifted to about 11cm -1 of wavenumbers to 1030 cm -1 which probably belong to C-O-H stretching of chitosan and acetate ion. The shifting of all the characteristic bands suggests that interactions has occurred and reaction has taken place between chitosan and [Bmim][OAc] [15]. The shifting toward higher wavenumbers of the C-O bonds in the C-O-C and C-O-H stretching vibration mode indicate the oxygen atoms in the polymer matrix are less hydrogen bonded.…”

Processing of Cellulose Using Ionic Liquids

“…The interaction of molecules of both polymers was confirmed by Holmberg et al [93] There are also a few patents describing methods of producing chitosan fibers from chitosan/IL solutions using alkylimidazolium-based ILs containing cations such as alkyl imidazolium salts and Cl − , ClCH 2 COO − , but also carboxylates such as CH 3 COO − as anions. [94] It has also been reported that blending cellulose with chitosan is possible with the aid of a mixture of glycine hydrochloride and 1-butyl-3-methylimidazolium chloride. [95] Such fibers show higher tensile strength in comparison to regenerated cellulose fibers but reduced elongation at break.…”