Study On Bleaching Of The Starch Glycoside Surfactant

The starch glycoside surfactant which synthesisd by starch and vegetable oil is an new kind of green surfactant. As a bio-based starch glycoside surfactant, Starch glycoside surfactant not only have traditional chemical-based surfactants excellent performance but also non-toxic, non-irritating, biodegradable and other unique properties, getting more and more popular in many areas. Due to the harsh synthesis conditions as well as the complicated components of starch,the starch glycoside surfactant products show an undesirably dark color during the synthesis and dealcoholization, which limit their commercial application. So, the developing novel technics for bleaching of starch glycoside surfactants have the great significance in the deep process of starch and starch glycoside surfactants industry.The paper is consists of three parts: the optimal process for the synthesis of alkyl chain length of starch glycoside C₈^C₁₀ surfactant are improved on dealcoholization and neutralization,Determining optimum content of additives;The technic of decoloration was optimized through the orthogonal experimentation which can be achieve the GB-standard; Improved decoloration additives, developed a more cost-effective route which the Solid content, the content of free fatty alcohol, viscosity, average degree of polymerization, pH, Inorganic salt content are complied with the GB-standard, and achieve first grade by the agency test.This experiment shows that: The optimal neutralization is MgO, The optimal dosage of MgO is 1.0%, the absorbance is 0.159 under the 470nm.the absorbance is decreased by adding NaBH₄ before dealcoholization, optimal dosage of MgO is 1%, NaBH₄ is 1.5%, the absorbance is 0.079 under the 470nm.The optimal conditions of decolorization: hydrogen peroxide 8%, temperature 80℃, the initial pH 10.the dosage of additives: Na₂SiO₃ is 0.6%,MgSO₄ is 0.05%,EDTA is 0.3%. the improved additives : Na₂SiO₃ is 0.2%,Urea is 0.3%,Sodium citrate is 0.2%. the experiment shows that Solid content, free fatty alcohols, viscosity, average degree of polymerization, inorganic salt content of starch glycoside surfactant are not changed before and after bleaching.