Syntheses of some sulfur- and phosphorus-containing carbohydrate polymer derivatives

Abstract

Tetraphosphorus decasulfide treatment of various carbohydrate polymers has been performed in the absence or presence of dimethyl formamide, affording materials with sulfur contents of about 2–22%, phosphorus contents of about 1–10%, and sulfur-to-phosphorus ratios of 0·2–5·6. These modifications are applied to cellulose, β-cyclodextrin and starch. The highest sulfur incorporations and S/P ratios are obtained when no solvent is employed. Conversely, maximum phosphorus incorporations and low S/P ratios are achieved when the reactions are conducted in dimethyl formamide. High sulfur contents appear to be correlated to derivatives with sulfide and thiophosphate substitutions, whereas high phosphorus contents are likely based on the predominance of phosphate residues. In a more conventional approach, sodium pyrophosphate has been employed for the phosphorylation of xanthan, chitin and chitosan, resulting in phosphorus incorporation levels of 4–7%.