| abstract |
Spinnable, shapable solutions of celluose are disclosed, wherein the solutions contain native cellulose in a mixture of dimethylsulphoxide (DMSO) and formaldehyde. The cellulose has a degree of polymerization (DP) of at least 400 and a concentration in the mixture of at least 6% by weight, based on the volume of DSMO. The formaldehyde/cellulose weight ratio is 0.2 to 2, and the solutions have a water content no greater than 5,000 ppm by weight. n The solutions are obtained by dissolving the cellulose in a mixture of DMSO and formaldehyde, at a formaldehyde/cellulose weight ratio of at least 1, and thereafter the formaldehyde/cellulose weight ratio is reduced, if necessary, to the final level of about 0.2 to 2. n The solutions can be converted into films, membranes, sponges, varnishes, paints, and especially into filaments, with the filaments being generally similar in properties to regenerated cellulose filaments. |