采用NaOH-一氯乙酸反应体系,异丙醇为溶剂对菊粉进行羧甲基化修饰。以取代度为评价指标,通过单因素及正交实验优化羧甲基化条件,并进行结构表征。结果表明:羧甲基化最佳条件为m(菊粉)∶m(一氯乙酸)∶m(氢氧化钠)=2.75∶1.4∶1,碱化时间4 min,醚化时间15 min,该条件下取代度为0.41。红外光谱与X-射线衍射分析表明羧甲基化工艺是可行的。

Carboxymethyl inulin(CMI) was prepared by ultrasonic-assisted method in NaOH-chloroacetic acid with isopropanol as the solvent.The effects of etherification time,alkalization time,solvent volume fraction and amount of NaOH on the degree of substitution(DS) of CMI were investigated.The suitable conditions were as follows:m(inulin):m(chloroacetic acid):m(sodium hydroxide) =2.75:1.4:1,alkalization time 4 minutes,etherification time 15 minutes.The DS of CMI was obtained as 0.41 under the optimum reaction condition.Structure confirmation of CMI was identified by infrared spectroscopy(IR) and X-ray diffracttometry(X-RD),which have proved that the modification method is feasible.