纤维素在离子液体[AMMor]Cl/[AMIm]Cl混合溶剂中的均相乙酰化反应研究

Study on the Homogeneous Acetylation of Cellulose in a Mixed Ionic Liquid of [AMMor]Cl/[AMIm]Cl

利用混配离子液体N-烯丙基-N-甲基吗啉氯盐(N-allyl-N-methylmorpholinium chloride,[AMMor]Cl)和1-烯丙基-3-甲基咪唑氯盐(1-allyl-3-methylimidazolium chloride,[AMIm]Cl)作为溶剂,乙酰氯为乙酰化试剂,研究了在没有催化剂条件下的纤维素的均相乙酰化反应.生成的醋酸纤维素(CA)的取代度由2.58到3.00.用FT-IR,1HNMR和13CNMR进行表征.结果表明,[AMMor]Cl/[AMIm]Cl混配的离子液体是一种良好的均相乙酰化介质,纤维素C-6,C-3和C-2三个位置上的羟基均发生了乙酰化反应,且得到纯的纤维素醋酸酯.此反应方便可控,简单高效,不仅降低了成本,离子液体比较容易回收,可以再次利用.

Homogeneous acetylation of cellulose was performed in a new mixed ionic liquid N-allyl-N-methylmorpholinium chloride（[AMMor]Cl） and 1-allyl-3-methylimidazolium chloride（[AMIm]Cl） in the absence of catalyst.The degree of substitution to cellulose acetates ranged from 2.58 to 3.00.The products were characterized by FT-IR,1H NMR and 13C NMR spectra.The results showed that modification of cellulose with acetyl chloride using [AMMor]Cl/[AMIm]Cl as solvent resulted in the production of cellulosic monoester,and the acetylation at C-6,C-3 and C-2 positions of the cellulose all occurred.The new homogeneous path gave pure cellulose acetates.All reactions were carried out under mild conditions,low excess of reagent and a short reaction time.The reaction media applied could be easily recycled.