纤维素作为一种最丰富的可再生自然资源具有很好的开发前景,但由于纤维素多氢键的超分子结构,致使其不溶于普通的有机溶剂,限制了其应用。而离子液体的出现为纤维素的应用提供了一个广阔的平台。本文综述了纤维素在咪唑类离子液体中的溶解性能及可能的溶解机理。总结指出阴离子为Cl-、CH3CHOO-和(MeO)RPO2-的离子液体对纤维素有较好的溶解能力;而烷基咪唑酯盐因一步合成、热稳定性好且溶解工艺简单等优点占有很大优势;咪唑阳离子的结构对溶解性也有很大影响。最后展望了该领域的发展前景。
Cellulose is the most abundant renewable bio-material.Due to its hydrogen-bonded supramolecular structure,cellulose is insoluble in water and most common organic liquids,which limits its application.The emergence of ionic liquids provides a broad platform to the application of cellulose.The recent developments concerning imidazolium ionic liquids as cellulose solvents as well as the dissolution mechanism are reviewed.Ionic liquids,containing Cl-,CH3CHOO-and(MeO)RPO2-anions,appear to be the most effective solvents.A series of alkyl imidazolium ionic liquids containing alkyl phosphate was prepared by a one-pot procedure.Such ionic liquids have good thermal stability and are capable of solubilizing cellulose under mild conditions.The structure of imidazolium cation has an influence on the solubility as well.Future development of imidazolium ionic liquids is discussed.