Hydration properties of regioselectively etherified celluloses monitored by ²H and ¹³C solid-state MAS NMR spectroscopy

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• 作者：Flemming H. Larsen^a ; ^{fhl@life.ku.dk} ; Michael Schö ; bitz^b ; ^c ; Jens Schaller^b
• 关键词：2 ; 3-O-hydroxypropylcellulose ; 2 ; 3-O-hydroxyethylcellulose ; Solid-state ; NMR ; Hydration ; Regioselective
• 刊名：Carbohydrate Polymers
• 出版年：2012
• 期刊代码：14_01448617
• 类别：ch
• 出版时间：20 June, 2012
• 卷：89
• 期：2
• 页码：640-647
• 文件大小：678 K

摘要

The hydration properties of 2,3-O-hydroxypropylcellulose (HPC) and 2,3-O-hydroxyethylcellulose (HEC) were analyzed by multi-nuclear solid-state MAS NMR spectroscopy. By ¹³C single-pulse (SP) MAS and cross-polarization (CP) MAS NMR, differences between the immobile regions and all parts of the polysaccharides were detected as a function of hydration. Complementary information about the water environments was observed by ²H MAS NMR. By this approach it was demonstrated that side chains in 2,3-O-HPC and 2,3-O-HEC were easier to hydrate than the cellulose backbone. Furthermore the motion of water was more restricted (slower) in 2,3-O-HPC than in 2,3-O-HEC. For both polysaccharides the hydration could be explained by a two-step process: in step one increased ordering of the immobile regions occurs after which the entire polymer is hydrated in step two.