采用N-甲基氧化吗啉(NMMO)/H_2O的纤维素均相溶解体系对羧甲基纤维素(CMC)的制备进行研究。通过~1H-NMR方法测定了羧甲基在脱水葡萄糖单元(AGU)上的取代情况,研究了醚化剂摩尔比、醚化时间及醚化温度对取代度(DS)和取代基分布的影响。结果表明,较优的NMMO/H2O均相羧甲基化工艺条件为:醚化剂摩尔比为10∶1,醚化时间为120 min,醚化温度为90℃,在此条件下取代度为1.26;羧甲基取代顺序表现为C(6)>C(2)>C(3),增加醚化剂用量和延长醚化时间可以促进C(2)和C(6)位的取代,提高反应温度更有利于提高C(6)的取代。与工业淤浆工艺所得的产品进行对比发现,NMMO/H2O均相体系制备的羧甲基纤维素产品具有更高的取代度和均匀的取代基分布。 The preparation of carboxymethylcellulose (CMC) was investigated using cellulose homogenous lysis system with N-methylmorpholine (NMMO) / H 2 O. The substitution of carboxymethyl groups on anhydroglucose units (AGU) was determined by ~ 1H-NMR. The effect of etherifying agent molar ratio, etherification time and etherification temperature on the degree of substitution (DS) and the distribution of substituents . The results showed that the optimum conditions of homogeneous NMMO / H2O carboxymethylation were as follows: the molar ratio of etherifying agent was 10:1, the etherification time was 120 min, the etherification temperature was 90 ℃, the degree of substitution under this condition was 1.26. The order of carboxymethyl substitution was C (6)> C (2)> C (3). Increasing the amount of etherifying agent and prolonging the etherification time promoted the substitution of C (2) and C (6) The reaction temperature is more conducive to improve the C (6) substitution. Compared with the products obtained from the industrial slurry process, the carboxymethyl cellulose products prepared by the NMMO / H2O homogeneous system have higher degree of substitution and uniform substituent distribution.