Abstract: Carboxymethyl starch, is an kind of important, widely used modified starch because of its excellent performance with good development prospects. This paper studies withwo methods which use corn starch as raw material, ethanol as solvent, and potato starch as raw material, isopropyl alcohol as solvent, chloroacetic acid as etherification agent to obtain powder high viscosity and hign degree of substitution carboxymethyl starch (CMS). And also examine the effect of volume of water, temperature, solvent and other factors to the degree of substitution and viscosity. The results showed that:in the experiment of isopropanol as solvent, potato starch as the raw material preparare CMS, at 50 ℃ degree of substitution and viscosity to achieve the best, and in a certain range, viscosity and inversely proportional to the amount of water added. And in the experiment of ethanol as solvent, corn starch as raw materials to prepare CMS,we found that the solvent had no significant effect on the product, while the viscosity increases with the amount of water and then decreased, and add 14g water can get the maximum viscosity . And found that add water in different periods of time also affects the viscosity, add water after make alkaline can increase viscosity visibly.
Keywords:Carboxymethyl starch Synthesis Degree of substitution(DS) Starch
CMS