Dissolution of cellulose in NaOH based solvents at low temperature

Mild condition dissolution of high molecular weight cotton cellulose in 1‐butyl‐3‐methylimidazolium acetate/N,N‐dimethylacetamide solvent system

“…Cotton shows typical diffraction peaks of native cellulose (cellulose I β ) at 2θ = 14.7, 16.4, 22.7, and 34.5° corresponding to the crystal latice of 1‐10, , , and , respectively . After dissolution and subquent regeneration in water, regenerated film exhibits characteristic diffraction pattern of cellulose II with diffraction peaks at 2θ = 12.04, 20.19, and 21.6° indicating the transformation of cotton cellulose from cellulose I to cellulose II consitent with what has been reported for most solvent systems for cellulose . Compared to the diffraction pattern of cotton cellulose, the intensity of the major diffraction peak, corresponding to the crystal lattice of which shifts towards lower 2θ and appears at 2θ = 21.6° in cellulose II, is drastically decreased in the regenerated film.…”

“…38,[47][48][49] After dissolution and subquent regeneration in water, regenerated film exhibits characteristic diffraction pattern of cellulose II with diffraction peaks at 2u 5 12.04, 20.19, and 21.68 indicating the transformation of cotton cellulose from cellulose I to cellulose II consitent with what has been reported for most solvent systems for cellulose. 14,38,45,50 Compared to the diffraction pattern of cotton cellulose, the intensity of the major diffraction peak, corresponding to the crystal lattice of 200 which shifts towards lower 2u and appears at 2u 5 21.68 in cellulose II, is drastically decreased in the regenerated film. The observed phenomenon suggests that the crystallinity of the regenerated film is lower than the original cotton cellulose.This behavior indicates that the BMIMAc/DMAc solvent system, at ambient conditions, is able to break the intra-and intermolecular hydrogen bonds between cellulose chains, thereby, disrupting the native crystalline structure in cotton cellulose.…”

The effect of zinc oxide (ZnO) addition on the physical and morphological properties of cellulose aerogel beads

“…35 Furthermore, the peak at 896 cm À1 becomes more intense and sharper during regeneration as bead in NaOH/urea/ZnO mixture, which clearly conrms that cellulose I is transformed to cellulose II. 32,36…”

Physical properties and fibrillation tendency of regenerated cellulose fiber dry jet-wet spun from high-molecular weight cotton linter Pulp/NMMO solution

“…Among the many alternative methods developed to reduce the processing steps as well as to minimize the hazardous byproducts, Lyocell is a new generic name given to regenerated cellulose fiber produced using N-methylmorpholine N-oxide (NMMO) dissolution followed by coagulation in an aqueous NMMO spinning bath [4]. Lyocell process provides an environmentallyfriendly, less toxic, and relatively simple method for producing regenerated cellulose fiber with excellent properties such as high dry and wet tenacity and high wet modulus, since it is manufactured by a closed-loop method which enables almost complete recovery of the non-toxic organic solvent [5][6][7][8]. In comparison, conventional wood pulp based Lyocell has several demerits such as forest destruction and easy fibrillation in the wet state due to high degree of crystallinity as well as higher orientation of cellulose chains in non-crystalline region of fibers [9][10][11].…”