Abstract: Aqueous solutions of an amine N-oxide such as N-methyl morpholine N-oxide used in the manufacture of regenerated cellulose can be purified by passage through a strongly basic anion-exchange resin. The resin is regenerated by treatment with (1) an aqueous solution of a strong inorganic acid such as hydrochloric or sulphuric acid and (2) an aqueous solution of sodium hydroxide.

Abstract: Shaped articles, such as fibres and films, are obtained from a polymer solution comprising cellulose, a solvent for the cellulose comprising a cyclic tertiary amine N-oxide and water, and a stabilizer for the solution selected from the group consisting of sodium hexametaphosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, hydroxy-ethylidene diphosphonic acid, aminoethyl diphosphonic acid, and complexes of such compounds with occluded metal ions present in the polymer solution. The stabilizer is present in an amount sufficient to stabilize the solution against thermal degradation which causes loss of solvent and discoloration of solvent and dissolved cellulose.