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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FT-IR、1HNMR、13CNMR和元素分析对结构进行了确证。首先用离子液体对壳聚糖碱化,再令碱化后壳聚糖与溴代十六烷进行烷基化反应,制备高取代度的N-十六烷基化壳聚糖。用FT-IR、XRD对烷基化产物进行了表征。考察时间、温度及物料配比对N-十六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∶1,40℃碱化1 h,n(溴代十六烷)∶n(碱化后壳聚糖)=2∶1,烷基化反应温度85℃,反应时间3.5 h,在该条件下十六烷基壳聚糖的取代度达到75%以上。离子液体具有重复使用性,反应后的离子液体重复使用3次后,N-十六烷基壳聚糖的取代度仍>75%。
1-methyl-3-butylimidazolium acetate ([Bmim] OAc), 1-methyl-3-butylimidazolium carbonate The structure of imidazolium hydroxide ([Bmim] OH) ionic liquid was confirmed by FT-IR, 1HNMR, 13CNMR and elemental analysis. Firstly, the chitosan is alkalized with an ionic liquid, and alkalization is performed to alkylate the chitosan and bromohexadecane to prepare N-hexadecylated chitosan with high degree of substitution. The alkylation products were characterized by FT-IR and XRD. The effects of time, temperature and material ratio on the degree of substitution of N-hexadecyl chitosan were investigated. The optimal reaction conditions were as follows: n ([Bmim] OH): n (chitosan raw material) 40 ℃ alkaline 1 h, n (bromohexadecane): n (basified chitosan) = 2: 1, alkylation temperature 85 ℃, the reaction time 3.5 h, under the conditions of cetane Chitosan substitution degree of more than 75%. Ionic liquid has reusability, the ionic liquid after the reaction was repeated three times, N-hexadecyl chitosan degree of substitution is still> 75%.