基于低共熔溶剂硫酸化改性的纤维素纳米纤丝的制备及性能分析

Preparation and Characterization of Sulfonated Cellulose Nanofibril Based on Deep Eutectic Solvent

关键词:  低共熔溶剂  纤维素纳米纤丝  硫酸化改性  润胀

Key Words:deep eutectic solvent  cellulose nanofibril  sulfation  swelling

摘要:本研究以漂白杨木化学浆为原料，采用氨基磺酸与甘油基低共熔溶剂（DES）结合超微粉碎处理制备硫酸化纤维素纳米纤丝（CNF）。探讨了预处理时间（1.0、1.5 h）、氨基磺酸与纤维素的摩尔比（20∶1、15∶1、10∶1）对纸浆纤维质量和CNF性能的影响。利用纤维质量分析仪、元素分析仪和傅里叶变换红外光谱仪对DES预处理前后的纸浆纤维结构进行了分析表征。结果表明，与未经过DES预处理的纸浆相比，经过DES预处理后纸浆纤维长度显著降低，最多降低72.67%，而纸浆纤维直径有所增加，最大增加26.82%。随着预处理时间的延长和氨基磺酸用量的增加，纸浆纤维长度降低，纸浆纤维的直径增大，纸浆纤维的硫含量增加，取代度（DS）提高至0.17。使用粒度分析仪、原子力显微镜、Zeta电位检测仪、X射线衍射仪和多重光散射分析仪对制备的CNF进行分析显示，DES预处理后，CNF的平均粒径减小，平均粒径最小为40.02 nm，CNF胶体的Zeta电位在 -43.50~-18.80 mV之间，结晶度降低，最低为58.51%，CNF悬浮液的稳定性提高。

Abstract:In this study， bleached chemical poplar pulp was used as raw material to prepare sulfonated cellulose nanofibril （CNF） using sulfamic acid and deep eutectic solvent （DES） pretreatment combined with superfine grinding. The effects of treatment time （1.0， 1.5 h） and molar ratio of sulfamic acid to cellulose （20 ∶ 1， 15 ∶ 1， 10 ∶ 1） on pulp fiber and CNF were investigated. The fiber quality analyzer， element analyzer， and infrared spectrometer were used to analyze and characterize the structure of pulp fiber before and after DES pretreatment. The results showed that compared with the pulp， fiber length of the pulp pretreated by DES was reduced with the maximum reduction of 72.67% while the diameter of which increased with the maximum increasement of 26.82%. With extension of the treatment time and increase of sulfamic acid amount， the length of the pulp fiber decreased， while the diameter， sulfur content， and degree of substitution （DS， to 0.17） of the pulp fiber pretreated with DES increased. The analysis of the prepared sulfonated CNF by particle size analyzer， atomic force microscope， Zeta potential detector， X-ray diffractometer， and multiple light scattering analyzer showed that after DES pretreatment， the average particle size of the sulfonated CNF decreased with the minimum value of 40.02 nm， the Zeta potential of sulfonated CNF colloid was between -43.50~ -18.80 mV， the crystallinity reduced with the minimum value of 58.51%， while the stability of the sulfonated CNF suspension improved.