氯化胆碱/马来酸低共熔溶剂预处理制备纤维素纳米晶

Preparation of Cellulose Nanocrystals Based on Choline Chloride/Maleic Acid Deep Eutectic Solvent

以氯化胆碱/马来酸低共熔溶剂预处理纤维素原料,并结合温和的机械剪切,制备了纤维素纳米晶(CNC),探究了不同氢键供受体物质的量比、预处理温度及反应时间对CNC得率的影响。利用透射电镜、红外光谱、X射线衍射、电导滴定和热重分析分别对CNC形态结构和热稳定性进行了表征。结果表明:氯化胆碱/马来酸(物质的量比2∶1)体系在100°C、6h条件下制备的CNC宽度可达(10.2±2.7)nm,得率为24.2%,其表面羧基含量达到0.39mmol/g。本研究成功制备了表面功能化的CNC,为低共熔溶剂纳米纤维素的绿色制备提供了思路。

In this study,cellulose nanocrystals(CNC)were prepared by using the choline chloride/maleic acid combined with mild mechanical shearing.The effects of different molar ratios,pretreatment temperatures and the reaction times on the yields of CNC were investigated.The morphology,structure and thermal stability were characterized by transmission electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction analysis,conductometric titration and thermogravimetric analysis.Results showed that CNC prepared by choline chloride/maleic acid(molar ratio 2∶1)system at 100°C for 6 h reached a width of(10.2±2.7)nm and a yield of 24.2%,and the content of carboxyl moieties on the surface of 0.39 mmol/g.The study successfully prepared the surface-functionalized CNC,which providesan effective and sustainable strategy for green preparation of nanocellulose.