干法制备中低取代度羧甲基淀粉

Dry Preparation of Medium and Low Degree of Substitution Carboxymethyl Starch

以木薯淀粉为原料,采用干法工艺制备了中低取代度的羧甲基淀粉,研究了各反应因素对羧甲基淀粉的取代度和反应效率的影响,确定了最佳工艺条件:CH2ClCOOH与淀粉的摩尔比为0.15,NaOH与CH_(2)ClCOOH的摩尔为4.0,反应体系中水的质量分数为20%,乙醇的质量分数为10%,反应温度为88~90℃,反应时间为2h。产物的取代度为0.25,反应效率为71%。

Applied tapioca starch as raw material,the dry process was used to prepare carboxymethyl starch with medium and low degree of substitution.The influence of various reaction factors on the degree of substitution and reaction efficiency of carboxymethyl starch was studied,and the optimum process conditions were obtained:ratio of CH2ClCOOH to starch molar was 0.15,the molar ratio of NaOH to CH2ClCOOH was 4.0,the mass fraction of water in the reaction system was 20%,the mass fraction of ethanol was 10%,the reaction temperature was 88~90℃,and the reaction time was 2h.The degree of substitution of the products was 0.25,the reaction efficiency was 71%.