水溶液
化学
纤维素
尿素
溶解度
质子核磁共振
特性粘度
核磁共振谱数据库
粘度
核化学
高分子化学
有机化学
聚合物
材料科学
谱线
复合材料
物理
天文
作者
Jinping Zhou,Qin Ye,Shilin Liu,Lina Zhang
标识
DOI:10.1002/mabi.200500148
摘要
Abstract Summary: Hydroxyethylcellulose (HEC) was synthesized by a fully homogenous method from cellulose in 7.5 wt.‐% NaOH/11 wt.‐% urea aqueous solutions under mild conditions. HEC samples were characterized with NMR, SEC‐LLS, solubility, and viscosity measurements. The MS and DS values of the obtained HEC samples are in the range from 0.54 to 1.44 and 0.45 to 1.14, respectively, and the relative DS values at C‐2 and C‐6 hydroxyl groups are slightly higher than those at C‐3 hydroxyl groups. HEC samples are soluble in water starting from a MS of 0.57 and DS of 0.49, which display high viscosity in aqueous solutions. Moreover, a NaOH/urea aqueous solution is a stable system for cellulose etherification. In this way, we could provide a simple, pollution‐free, and homogeneous aqueous solution system for synthesizing cellulose ethers. 13 C NMR spectra of acetylated HEC (a) in CDCl 3 at 40 °C and (b) in DMSO‐ d 6 at 100 °C. magnified image 13 C NMR spectra of acetylated HEC (a) in CDCl 3 at 40 °C and (b) in DMSO‐ d 6 at 100 °C.
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