首页 | 本学科首页   官方微博 | 高级检索  
     

纤维素在氢氧化锂/尿素水介质中的溶液性质研究
引用本文:王媛媛,闫立峰,李婉. 纤维素在氢氧化锂/尿素水介质中的溶液性质研究[J]. 中国科学技术大学学报, 2008, 38(6)
作者姓名:王媛媛  闫立峰  李婉
作者单位:中国科学技术大学化学物理系和合肥微尺度物质科学国家实验室,安徽,合肥,230026
基金项目:国家科技攻关项目 , 国家重点基础研究发展计划(973计划)
摘    要:纤维素可以在氢氧化锂/尿素的混合水介质中溶解.选取三种不同分子量的纤维素,在N,N-二甲基乙酰胺/氯化锂体系中进行溶解,并通过粘度法,准确确定其分子量.而后,在4.2%氢氧化锂与12%尿素的水介质中溶解它们.通过粘度法测定其特性参数,得到该溶液体系的M—H方程:[η]=1.695×10^-3Mη^0.914(mL·g^-1).并测定了体系的ML和q值分别为387.5nm^-1和6.1nm,显示纤维素在该溶剂中以半柔性链的形式存在.同时,采用SEM和POM(polarized optical microscopy)分别研究了纤维素在溶解前后结构的变化,同样证实在氢氧化锂/尿素体系中纤维素可以很好地被分散,且通过不同的组装方式形成新的集聚态结构.

关 键 词:纤维素  水溶液  粘度  分子量  cellulose  aqueous solution  viscosity  molecular weight  纤维素  氢氧化锂  尿素  水介质  溶液性质  研究  LiOH  cellulose  studies  Solution  aqueous solution  take  place  during  process  results  measurements  exist  chains  established

Solution studies of cellulose in LiOH/urea aqueous solution
WANG Yuan-yuan,YAN Li-feng,LI Wan. Solution studies of cellulose in LiOH/urea aqueous solution[J]. Journal of University of Science and Technology of China, 2008, 38(6)
Authors:WANG Yuan-yuan  YAN Li-feng  LI Wan
Abstract:LiOH/urea aqueous is a attractive solvent system for cellulose. The solution properties of cellulose in the solvent at low concentration were investigated. Three kinds of cellulose with different molecular weights were dissolved in 4.2 wt% LiOH/12 wt% urea aqueous solution and LiC1/DMAc solvent system, respectively. The dilute solution behavior of cellulose in LiOH/urea aqueous solution was examined by viscometry measurement. The Mark-Houwink equation for cellulose in 4.2 wt% LiOH/12 wt% urea aqueous solution at 25℃ over the Mη range from 14.9×104 to 32.8)< 104 was established as follows: [η] = 1.695×10-3 M0.914η (mL·g-1 ), which implies that the cellulose molecules exist as semi-flexible chains in the aqueous solution. The topographies of both cellulose and regenerated cellulose from its solution were also studied by SEN[ and POM (polarized optical microscopy) measurements. The results reveal that the cellulose can be well dissolved in the LiOH/urea aqueous solvent system, and self-association should take place during the depositing process.
Keywords:cellulose  aqueous solution  viscosity  molecular weight
本文献已被 维普 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号