高取代度木薯羧甲基淀粉的合成及表征

以机械活化60min的木薯淀粉为原料,采用乙醇溶剂法合成了高取代度的木薯羧甲基淀粉.通过正交实验优化羧甲基淀粉的合成工艺条件,探讨了反应时间、反应温度、催化剂用量、醚化剂用量、乙醇浓度及淀粉乳浓度等因素对羧甲基淀粉取代度的影响.结果表明,其合成的最优工艺条件为:反应温度50℃,乙醇浓度90%,反应时间120min,ClCH2COOH与淀粉摩尔比0.80,淀粉乳浓度35%(ω),NaOH与淀粉摩尔比0.80.在此条件下合成的羧甲基淀粉的取代度为1.24.并对产物的结构进行了表征.

Synthesis and Characterization of High Degree of Substitution Cassava Carboxymethyl Starch

Carboxymethyl starch (CMS) with high degree of substitution (D_S) was synthesized by ethanol method, using cassava starch activated for 60 min as material. The process conditions were optimized by orthogonal experiments, the effects of reaction time, reaction temperature, catalyst amount, etherifying agent amount, concentration of ethanol and concentration of starch on D_S of CMS were investigated. The results indicated that the optimized conditions for synthesis of high D_S cassava CMS were temperature 50℃, concentration of ethanol 90%, reaction time 120 min, molar ratio of ClCH_2COOH to starch 0.80, concentration of starch 35%(w) and molar ratio of NaOH to starch 0.80. The value of D_S was 1.24 under the synthetic conditions. Furthermore the product was further characterized.