THE SOLUBILITY OF CELLULOSE IN LIQUID AMMONIA-SALT SOLUTIONS

In the reported experimental study, the dissolution of cellulose in solutions of liquid ammonia and ammonium thiocyanate was investigated. Viscosity measurements on dilute solutions of cellulose in this solvent over a range of shear rates and shear stresses are reported. A four-bulb Ubbelohde suspended level viscometer was used for the measurements. Plots of log left bracket eta right bracket versus log M gave Mnark-Houwink coefficients of a equals 0. 95 and K equals 6. 686 multiplied by 10** minus **5 at 25 degree C for left bracket eta right bracket as dl/g. The Bloomfield equation was used to calculate effective bond lengths (b) from limiting viscosity numbers of cellulose in solutions of ammonia/ammonium thiocyanate and Cuene, respectively. Results indicate that cellulose may have similar configurations in both solvents and also that the ammonia solutions are true cellulose solutions. Miscibility of the cellulose/ammonia/ammonium thiocyanate solutions with organic solvents, such as glycerol, is also reported. Further, a few interesting characteristics of the liquid ammonia/ammonium salt solutions, discussed briefly, are the convenient boiling point, the rheological behavior, and the relatively high concentration of cellulose obtainable.