Synthesis and Optimization of the Reaction Conditions of Starch Sulfates in Aqueous Solution

Abstract Starch sulfate was prepared by chemical modification of potato starch with trisulfonated sodium amine (N(SO3Na)3), which was synthesized by reaction of sodium bisulfite and sodium nitrite in aqueous solution. The factors that could affect the degree of substitution (DS) of potato starch were investigated in detail, which included reaction temperature and time of preparing the sulfating agent, reaction temperature and time of synthesizing the starch sulfate, dosage of sulfating agent and potato starch, pH of sulfation reaction medium, and the ratio of liquid volume to starch mass. A starch sulfate with DS of 2.14 was obtained under optimal conditions. FTIR spectra showed the characteristic absorptions of sulfate ester bonds at 1236 cm−1 and 821 cm−1.