N-烯丙基吡啶氯盐离子液体/有机溶液复合溶剂对纤维素的溶解性能

采用一步法合成N-烯丙基吡啶氯盐离子液体(APy]Cl),用红外光谱(FT-IR)和核磁共振(1H-NMR)进行结构表征,并与常用有机溶液(二甲基亚砜(DMSO)、N,N-二甲基甲酰胺(DMF)、N,N-二甲基乙酰胺(DMAc)及吡啶)配成复合溶剂,测定并比较对棉浆粕的溶解能力。结果表明,四种复合溶剂均为纤维素的优良溶剂,其中在APy]Cl/DMAc复合溶剂中溶解性能最佳,在100℃、DMAc质量分数为40%时,溶解度能达到12.25%。利用FT-IR、X射线衍射(XRD)和热重分析(TGA)对溶解再生前后纤维素膜的结构进行分析。结果表明,四种复合溶剂均为纤维素的直接溶剂,可将晶型由Ⅰ转变成Ⅱ,热稳定性良好。

The Dissolution of Cellulose in N-Allylpyridinium Chloride Ionic Liquid/Organic Solvent

N-allylpyridinium chloride ionic liquid(Cl) was synthesized by one-step process,and its structure was characterized by 1H nuclear magnetic resonance spectrum(1H-NMR) and Fourier transform infrared spectra(FT-IR).The dissolubilities of cotton pulp in Cl/common solvents(dimethylsulfoxide(DMSO),N,N-dimethylformamide(DMF),N,N-dimethylacetamide(DMAc) or pyridine) were measured and compared.The results show that four kinds of compound solvents are excellent solvent for cellulose,and the solubility in Cl/DMAc is better than in several other solvents under the same conditions.When the content of DMAc is 40%,the solubility of cotton pulp is up to 12.25% at 100 ℃.The original cellulose and the regenerated cellulose were analyzed by FT-IR,Xray diffraction(XRD) and thermogravimetric analysis(TGA),respectively.The results show that these compound solvents are non-derivatizing solvents for cellulose and,make the crystal form of regenerated cellulose transform from celluloseⅠto celluloseⅡ.Furthermore,the regenerated cellulose shows good thermal stability.