Solution states of cellulose in selected direct dissolution agents

Abstract

Properties of cellulose solutions in different direct dissolving liquids such as N-methylmorpholine-N-oxide and ionic liquids with varied cations and anions were investigated. The effects of different cations and anions of the used ionic liquids on the solution state were studied on the basis of the rheological characteristics of the resulting polymer solutions. The influence of these components is discussed in terms of zero shear viscosities, master curves with storage and loss moduli as well as complex viscosities using comparable molar ratios between cellulose and solvent and comparable polymer concentrations. Furthermore anisotropic properties of highly concentrated cellulose solutions were determined by means of polarised light microscopy and rheological methods subjected to the used solvent and variation of the polymer concentration as well as the temperature.

Homogeneous Acetylation of Cellulose in the New Solvent Triethyloctylammonium Chloride in Combination with Organic Liquids

“…The additional use of pyridine as base and performing the reaction at 80 °C for 2 h yields higher DS values of up to 3.0. The acetylation of cellulose in imidazolium‐based ILs could also be used for direct conversion of the product to fibers by dry/wet spinning without previous isolation of the cellulose acetate formed …”

Ionic liquids: Efficient solvent and medium for the transformation of renewable lignocellulose

“…In addition, 3-alkyl-1-methyl imidazolium salt ILs incorporating acetate, propionate, and diethylphosphate anions were also used to dissolve cellulose, and the effect of cations and anions was intensively investigated [27,28]. Results showed that these ILs have a much better capability to dissolve cellulose than chloride salt ILs or conventional N-methyl-morpholine-N-oxide monohydrate solutions.…”

3D Printing Cellulose Hydrogels Using LASER Induced Thermal Gelation

“…Other applications relying on structured porous hydrogels, such as stationary phases for liquid chromatography [10][11][12][13], membranes or microfluid devices are other possible application ranges for highly structured cellulosic materials [14]. However, processability, and especially "printability" is strongly limited by the necessity of using an appropriate solvent to shape cellulose, as it is not melt-processable [15], and thus, the 3D printing of cellulose is mostly unexplored. To extend the application potential of cellulose hydrogels in analogy with other biopolymers, new methods need to be found that allow its 3D printing.…”