纤维素在1-烯丙基-3-甲基咪唑氯盐中溶解机理

通过分析纤维素/1-烯丙基-3-甲基咪唑氯盐(AmimCl)溶液在不同温度下浊度的变化和红外谱图变化,研究了纤维素在AmimCl中的溶解机理。温度升高,浊度变大,红外谱图羟基特征峰向高波数移动,说明纤维素与AmimCl的相互作用是氢键,而且温度升高会破坏纤维素/AmimCl溶液中的氢键,从而导致纤维素在AmimCl中析出。向纤维素/AmimCl溶液加入尿素、LiCl、KH_2PO_2、K_2SO_4和KPF_6等不同的氢键受体,用核磁共振方法研究了这些氢键受体与AmimCl的相互作用,核磁研究表明,氢键受体与AmimCl相容性越好,溶解纤维素能力越大,进一步说明了纤维素与AmimCl间的氢键作用。根据这一结论,指导合成了3种新型离子液体,并考察了这些溶剂体系对于纤维素的溶解性。

Dissolution Mechanism of Cellulose in 1-Allyl-3-Methylimidazolium Chloride

In this paper,the dissolution mechanism of cellulose in 1-allyl-3-methylimidazolium chloride was studied by turbidimetry and infrared spectroscopy at different temperatures.The results indicate that the turbidity of cellulose/AmimCl solution increases and the peak position shifts to a higher wavenumber and consequently the cellulose precipitates with increasing temperature,due to destruction of the hydrogen bonds.The interaction between AmimCl solution and different hydrogen bond acceptors such as urea,LiCl,K2HPO2 and K2SO4 were investigated by turbidimetry and NMR spectroscopy,which indicate that the interaction between cellulose/AmimCl is hydrogen bond.The excellent compatibility of the hydrogen bond acceptors with AmimCl dissolves more cellulose.In addition,three novel ionic liquids with similar anionic structure of hydrogen bond acceptors were synthesized and the solubility of these solvent systems for cellulose was investigated.