THE DIVERGENT BEHAVIOR OF THE HYDROXIDES OF LITHIUM, SODIUM, AND OF POTASSIUM, RUBIDIUM, AND CESIUM IN THE XANTHATION OF CELLULOSE AND STARCH

Abstract

When a suspension of cellulose, or a solution of starch, in 17.8% aqueous sodium hydroxide was shaken with a large excess of carbon disulphide, a sodium xanthate of degree of substitution (D.S.) about 0.4 was obtained. The replacement of the sodium hydroxide by 17.8% potassium hydroxide resulted in a product of D.S. about 1.3. Plots were made of the D.S. of cellulose xanthate resulting from the use of various concentrations of the hydroxides of lithium, sodium, potassium, rubidium, and cesium; the plots for the last three hydroxides were similar, and differed sharply in form from those of the first two.Potassium cellulose or starch xanthate of D.S. about unity was freely soluble in water as well as in aqueous alkalies and the solutions "ripened". When immersed in methyl iodide, the dry salts yielded the corresponding S-methyl xanthates without change in the D.S. These S-methyl xanthates were white substances insoluble in water but dissolved or dispersed by carbon disulphide. They could be acetylated with sulphuric acid as catalyst and without change in the S-methyl xanthate D.S. The acetylated cellulose derivative was freely dispersed by chloroform or trichloroethylene.