https://www.rsc.org/suppdata/gc/b7/b713289a/suprev.pdf

Cellulose dissolution with polar ionic liquids under mild conditions: required factors for anions

The chemistry of side reactions and byproduct formation in the system NMMO/cellulose (Lyocell process)

The lattice theory of liquids consisting of rodlike molecules is presented and discussed with emphasis on polymers exhibiting nematic or cholesteric liquid crystallinity. Steric repulsions between the solute particles are principally responsible for order in lyotropic liquid-crystalline systems. In the case of rigid rods, the axial ratio of the particles governs the concentration at which separation of a nematic or cholesteric phase sets in. For semi-rigid chains such as those of cellulose and its derivatives, the axial ratio of the Kuhn segment is the relevant parameter. These and other predictions of the lattice theory are confirmed by numerous experiments. Liquid crystallinity may be promoted by orientation-dependent intermolecular attractions between extended chain molecules. Such forces originate in the anisotropy of the polarizabilities of groups, e.g., phenylene, in the main chain. They may be especially important in thermotropic melts and concentrated solutions.

Molecular theory of liquid crystals

Surface acylation of cellulose whiskers by drying aqueous emulsion.

A novel method for the determination of carbonyl groups in cellulosics by fluorescence labeling. 3. Monitoring oxidative processes.

Cellulose mesophases were obtained by preparing concentrated solutions of cellulose (20–55%) in a mixture of N-methyl-morpholine N-oxide (MMNO) and water. The anisotropy depends on four interconnected parameters: the temperature of the solution which, in general, must be lower than 90°C; the concentration of cellulose which must exceed 20%; a water content such that the mole ratio water/anhydrous MMNO is smaller than unity; and the degree of polymerization of the dissolved cellulose. The anisotropic cellulose solutions can readily be oriented during extrusion or casting thus giving fibers or films which upon regeneration exhibit high orientation.

S. Chaunis

Papers

Oriented cellulose films and fibers from a mesophase system