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Analysis of positions of substitution of O-acetyl groups in partially O-acetylated cellulose by the reductive-cleavage method

✍ Scribed by Chang Kiu Lee; Gary R. Gray

Publisher: Elsevier Science
Year: 1995
Tongue: English
Weight: 444 KB
Volume: 269
Category: Article
ISSN: 0008-6215
DOI: 10.1016/0008-6215(94)00354-i

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✦ Synopsis

Described herein are methods for determining the degree of substitution (ds) and the positions of substitution of O-acetyl groups in commercial samples of partially O-acetylated cellulose. Sequential neutral methylation of the polymers, base-catalyzed ethylation, and reductive cleavage gives eight products that are analyzed as their O-acetyl derivatives by gas-liquid chromatography. Alternatively, the permethylated polymers are subjected to reductive cleavage directly, under conditions that reduce O-acetyl groups to O-ethyl groups, to give the same eight products. The ds values obtained by these two methods were in good agreement with values obtained by integration of the O-acetyl and O-trimethylsilyl resonances of the fully O-trimethylsilylated polymers.

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