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合成了1-甲基-3-丁基咪唑醋酸盐([Bmim]OAc)、1-甲基-3-丁基咪唑碳酸盐([Bmim]2CO3)及1-甲基-3-丁基咪唑氢氧化物([Bmim]OH)离子液体,由FTIR、1HNMR和元素分析对其结构进行了确证。首先,用离子液体对壳聚糖碱化,再用碱化后壳聚糖与溴代十二烷进行烷基化反应,制备了高取代度的N-十二烷基化壳聚糖。用FTIR、1HNMR、XRD对烷基化产物进行了表征。考察了时间、温度及物料配比对N-十二烷基壳聚糖取代度的影响,得到较佳的反应条件:n([Bmim]OH)∶n(壳聚糖原料)=3∶1,45℃碱化1 h,n(溴代十二烷)∶n(碱化后壳聚糖)=2∶1,烷基化反应温度80℃,反应时间3 h,在该条件下十二烷基壳聚糖的取代度达到81%以上。离子液体重复使用3次后,N-十二烷基壳聚糖的取代度仍大于80%。
1-methyl-3-butylimidazolium acetate ([Bmim] OAc), 1-methyl-3-butylimidazolium carbonate The structure of imidazolium hydroxide ([Bmim] OH) ionic liquid was confirmed by FTIR, 1HNMR and elemental analysis. Firstly, alkylating chitosan with ionic liquid and alkylating chitosan with bromododecane after alkalization to prepare N-dodecylated chitosan with high degree of substitution. The alkylation products were characterized by FTIR, 1HNMR and XRD. The effects of time, temperature and material ratio on the degree of substitution of N-dodecyl chitosan were investigated. The optimum reaction conditions were as follows: n ([Bmim] OH): n , Basified at 45 ℃ for 1 h, n (bromododecane): n (alkalized chitosan) = 2: 1, alkylation reaction temperature was 80 ℃, reaction time was 3 h, under these conditions, The degree of substitution of alkyl chitosan reaches above 81%. The degree of substitution of N-dodecyl chitosan is still more than 80% after the ionic liquid is repeatedly used three times.