Cellulose

, Volume 21, Issue 1, pp 167–176

SEC-MALLS analysis of TEMPO-oxidized celluloses using methylation of carboxyl groups

  • Ryoya Hiraoki
  • Hayaka Fukuzumi
  • Yuko Ono
  • Tsuguyuki Saito
  • Akira Isogai
Original Paper

DOI: 10.1007/s10570-013-0090-5

Cite this article as:
Hiraoki, R., Fukuzumi, H., Ono, Y. et al. Cellulose (2014) 21: 167. doi:10.1007/s10570-013-0090-5
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Abstract

Two cellouronic acids [sodium (1 → 4)-β-polyglucuronates, CUAs] and one 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized wood cellulose (TOC) became soluble in 8 % lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) after the methylation of C6 carboxyl groups in these samples using trimethylsilyldiazomethane (TMSD). The obtained solutions were diluted to 1 % LiCl/DMAc and subjected to size-exclusion chromatography combined with multi-angle laser-light scattering (SEC-MALLS). Neither depolymerization nor side reactions took place during methylation; this was confirmed by SEC-MALLS and nuclear magnetic resonance analyses, using CUAs as models. The SEC-MALLS analysis of the original wood cellulose and the carboxyl-methylated TOC prepared from it, using 1 % LiCl/N,N-dimethyl-2-imidazolidinone and 1 % LiCl/DMAc, respectively, as eluents, showed that the weight-average degree of polymerization of the original wood cellulose decreased from 3,100 to 2,210 through TEMPO-mediated oxidation. The molecular-mass distributions of the original wood cellulose and the TOC both consisted of one large peak with a small shoulder, indicating that some of the oxidized hemicelluloses remained in the TOC. The combination of methylation of carboxyl groups in polysaccharides using TMSD and subsequent SEC-MALLS analysis using 1 % LiCl/DMAc as an eluent may be applicable not only to TOCs, but also to other polysaccharides with carboxyl groups, for evaluation of their molecular-mass parameters.

Keywords

TEMPO-oxidized cellulose Cellouronic acid Methyl ester Trimethylsilyldiazomethane SEC-MALLS LiCl/DMAc 

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Ryoya Hiraoki
    • 1
  • Hayaka Fukuzumi
    • 1
  • Yuko Ono
    • 1
  • Tsuguyuki Saito
    • 1
  • Akira Isogai
    • 1
  1. 1.Graduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan

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