棉浆纤维素/质子型离子液体溶液的流变行为  

Rheological behavior of cotton pulp cellulose/protic ionic liquid solutions

作　　者：马凯 邓璐璐 王学琳 石国民 邹光龙[1] MA Kai;DENG Lulu;WANG Xuelin;SHI Guomin;ZOU Guanglong(School of Chemical Engineering,Guizhou Minzu University,Guiyang,Guizhou 550025,China;School of Engineering,Westlake University,Hangzhou,Zhejiang 310024,China)

机构地区：[1]贵州民族大学化学工程学院,贵州贵阳550025 [2]西湖大学工学院,浙江杭州310024

出　　处：《纺织学报》2024年第5期10-18,共9页Journal of Textile Research

基　　金：国家自然科学基金项目(21363004);贵州民族大学自然科学基金项目(GZMUZK[2021]YB04);贵州省高等学校“绿色化学与资源环境创新团队”项目(黔教技[2022]13号)。

摘　　要：为实现棉浆纤维素的绿色、高效溶解,促进其高值化利用,以质子型离子液体([DBNH][Lev])为溶剂,制备了5种不同质量分数的纤维素/[DBNH][Lev]溶液;借助核磁共振技术研究了纤维素在离子液体中的溶解机制,测定了纤维素溶液在不同条件下的稳态和动态流变行为,讨论了纤维素含量、温度和剪切速率等对均相聚合物溶液黏度的影响规律。结果表明:纤维素/[DBNH][Lev]溶液为典型的假塑性流体,对温度具有敏感性,且黏度随温度升高而降低;此外,该溶液在高频率下出现凝胶点,存在黏性流动为主的类液态向弹性形变为主的类固态转变,且温度越高转变点越向低频区移动,这为纤维素在离子液体中的流变响应提供理论基础,并对后续的纤维素加工工艺(如涂层、纺丝)提供技术指导。Objective Cellulose is one of the most abundant renewable natural polymers but cannot be effectively dissolved by traditional solvents owing to its highly ordered hydrogen-bond network structure and high crystallinity,which limits the further development and large-scale application of cellulose.Ionic liquids with special structures,due to their strong hydrogen-bond breaking ability,are widely used as a green and efficient solvent for natural polymer dissolution and processing.However,few studies are conducted on protic ionic liquid([DBNH][Lev])concerning the dissolution of cellulose and their solution properties.What′s more levulinic acid derived from biomass resources endows green properties to[DBNH][Lev].Method Protic ionic liquid was used as solvent to achieve the efficient dissolution of cotton cellulose under mild conditions.The dissolution mechanism of cellulose in ionic liquid and the steady and dynamic rheological behavior of cellulose solution were systematically studied by using nuclear magnetic resonance and rheological techniques respectively.The influence of factors such as cellulose concentration,shear rate,and temperature on the rheological behavior of cellulose/[DBNH][Lev]solution was thoroughly investigated.The morphology and mechanical properties of generated films from cellulose/PILs solution were studied in view of their potential application.Results The rheological properties of cellulose are closely related to solvent category,cellulose concentration,cellulose molecular weight and experimental temperature.Firstly,it was identified that[DBNH][Lev]presented satisfactory dissolution ability to cellulose and had good solubility up to 5%to cellulose at 100℃.The ketone group in the Lev anion may provide a new hydrogen-bonding acceptor and donor in[DBNH][Lev]due to the keto-enol tautomerism,thus strengthening the interaction via hydrogen bonds between cellulose and[DBNH][Lev].The steady-state rheological curves of cellulose/[DBNH][Lev]solutions with different mass concentrations at 25℃.For al

关 键 词：棉浆纤维素 质子型离子液体 溶解 流变行为 Cox-Merz定律 黏弹性 

分 类 号：O633.4[理学—高分子化学]