【摘要】 建立低粘度的离子液体与质子型有机溶剂混合体系,考察纤维素在该体系中的溶解性。结果表明,3种有机溶剂二甲基亚砜(DMSO)、二甲基甲酰胺(DMF)、二甲基乙酰胺(DMAc)都有助于降低混合体系的粘度,当有机溶剂质量分数为20%时,混合体系粘度下降50%。纤维素在质量分数为20%的二甲基亚砜/1-乙基-3-甲基咪唑醋酸盐混合体系(DMSO/[Emim]Ac)中溶解性最佳,高聚合度(DP 1460)的松木纤维90℃下的溶解度从未添加DMSO时的5.0g/100g提高到7.5g/100g,溶解时间减少;红外光谱证实,DMSO/[Emim]Ac混合体系为纤维素的非衍生化试剂,X衍射表明,松木纤维经过溶解再生后发生了从纤维素Ⅰ型到纤维素Ⅱ型的晶型转变。更多还原

【Abstract】 A complex solvent with reduced viscosity was established by mixing ionic liquid and the protic organic solvents.The dissolving and solution property of cellulose in the complex solvent was studied.Results demonstrated that DMSO,DMF,and DMAc can effectively reduce the viscosity of the mixing system.The viscosity was fell by almost half when the mass fraction of 20% organic solvent.And the viscosity of the mixing system of the three organic solvents decreased 50%.But the optimum solubility of cellulose was gained in the mixing system with a mass ratio of DMSO/[Emim]Ac 20%.The solubility of the pine cellulose with a high polymerization degree of 1460 increased from 5.0g/100 g to 7.5g/100 g when 20%(w/w)DMSO was added to[Emim]Ac at 90 ℃,dissolution time reduced.It was confirmed by the infrared spectra that cellulose can be uniformly dissolved in the DMSO/[Emim]Ac mixture without derivation.X-ray diffraction spectra indicated that crystalline form of pine cellulose transformed completely from typeⅠ to typeⅡ after regeneration from ethanol.更多还原