干法制备高取代度高黏度羧甲基淀粉

以马铃薯淀粉和氯乙酸钠为原料,通过分阶段碱化和醚化方法,采用先进的干法工艺制备了高取代度、高黏度的羧甲基淀粉。并详细考察了氯乙酸钠用量、碱用量、反应温度及时间等条件对产品取代度和黏度的影响。实验结果表明,当淀粉、氯乙酸钠及氢氧化钠摩尔比为1:1:1．25时,在碱化和醚化反应温度、时间分别为35℃、 60 min和70℃、2．5 h条件下,可制备出取代度最高达0．73,反应效率为73％,黏度可达11 600 mPa·s的高取代度、高黏度羧甲基淀粉。

Preparation of Carboxymethyl Starch with High Degree of Substitution and High Solution Viscosity

The carboxymethyl starch with high degree of substitution and high solution viscosity was prepared via reaction of starch with sodium chloroacetate using dry process. The process consist of two steps, alkalinization and etherification. The optimal reaction conditions were: starch, sodium chloroacetate and sodium hydroxide in molar ratio 1:1:1. 25 , alkalinization at 35℃ for 60 min and etherification at 70 ℃ for 2. 5 h. The degree of substitution was 0. 73 ,the reaction efficiency was 73% and the solution viscosity was higher than 11 600 mPa·s.