机械活化木薯淀粉干法制备羧甲基淀粉的研究

Studies on Preparation of Carboxymethyl Starch from mechanic-activated Cassava Starch by a Dry Process

研究了以机械活化60 min的木薯淀粉为原料,采用干法工艺制备羧甲基淀粉(CMS)。探讨了机械活化时间、反应时间、反应温度、催化剂用量、醚化剂用量及体系含水量对木薯羧甲基淀粉取代度(DS)的影响。实验结果表明,机械活化对木薯淀粉的羧甲基化反应有显著的强化作用:木薯淀粉的DS随活化时间的延长而增大。活化60 min的样品在条件为反应时间120 min、ClCH2COOH与淀粉的摩尔比0.55、NaOH与淀粉的摩尔比0.55、反应温度60℃、体系含水量18%时制得的CMS的DS为0.88%,而在相同条件下,由原木薯淀粉制得的CMS的DS仅为0.23%。

Carboxymethyl starch （CMS） was prepared by a dry method from cassava starch mechanic - activated for 60 rain. The effects of mechanical activation time, reaction time, reaction temperature, catalyst amount, etherifying agent amount and system water content on degree of substitution （DS） of carboxymethyl starch were investigated. The results indicated that mechanical activation con- siderably enhanced carboxy methylation reaction of cassava starch, the content of DS in cassava starch increased with the activation time. When the reaction time was 120 rain, the mole ration of CICH2COOH to the starch was 0.55, the mole ration of NaOH to the starch was 0.55, the reaction temperature was 60~C, the system water was 18%, the content of DS from cassava starch activated for 60min was 0.88%, while it was only 0.23% from native starch at the same preparation conditions.