基于三元DES体系制备硫酸化改性CNF及其性能研究

Preparation and Properties of Sulfated CNF Based on Ternary DES System

中文关键词:  纤维素纳米纤丝  氨基磺酸/尿素/氯化胆碱  低共熔溶剂  改性

Key Words:cellulose nanofibril  sulphamic acid/choline chloride/urea  deep eutectic solvents  modification

中文摘要:

      以漂白硫酸盐浆为原料，采用氨基磺酸/尿素/氯化胆碱三元低共熔溶剂（DES）体系预处理结合机械处理的方法制备硫酸化改性的纤维素纳米纤丝（CNF），并采用纤维图像分析仪、元素分析仪、场发射扫描电子显微镜、原子力显微镜、傅里叶变换红外光谱仪、Zeta电位分析仪、热重分析仪和多重光散射分析仪对制得的CNF性能进行表征。结果表明，三元DES预处理既可改性纤维原料又可对其产生润胀效果，从而促进其在纳米均质化过程中的纤丝化。与未经DES预处理的纤维原料在均质化处理过程中能耗（9.49×10⁷ kJ/kg）相比，DES预处理（1.61×10⁷~2.11×10⁷ kJ/kg）可节省77.8%~83.0%的能耗。DES预处理提高了所得CNF悬浮液的稳定性但导致其热稳定性下降；此外，延长DES预处理时间可促进纤维的纤丝化并降低纤维聚合度。

Abstract:

      Cellulose nanofibers （CNF） were prepared from bleached kraft pulp fibers by the method of deep eutectic solvents （DES） system pretreatment combined with mechanical treatment. The properties of the prepared CNF were characterized by fiber quality analyzer， elemental analyzer， field-emission scanning electron microscope， atomic force microscope， Fourier transform infrared spectrometer， Zeta potential， thermal gravimetric， and multiple light scattering analyzers. The results showed that DES pretreatment not only modified fiber raw material but also swollen it， thus promoting the filamentation of fibers during the nano-homogenization process. The energy consumption of fiber raw materials homogenized without DES pretreatment was 9.49×10⁷ kJ/kg， and those of its DES pretreated counterparts were 1.61×10⁷~2.11×10⁷ kJ/kg， reducing 77.8%~83.0%. DES pretreatment improved the stability of CNF suspension but impaired its thermal stability. The increase in DES pretreatment time promoted the fibrillation of fibers but reduced the polymerization degree of fibers.