Solution-State One- and Two-Dimensional NMR Spectroscopy of High-Molecular-Weight Cellulose

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Ashley J. Holding
  • Valtteri Mäkelä
  • Lasse Tolonen
  • Herbert Sixta

  • Ilkka Kilpeläinen
  • Alistair W T King

Research units

  • University of Helsinki

Abstract

High-molecular-weight celluloses (which even include bacterial cellulose) can be dissolved fully in methyltrioctylphosphonium acetate/[D6]DMSO solutions to allow the measurement of resonance-overlap-free 1D and 2D NMR spectra. This is achieved by a simple and non-destructive dissolution method, without solvent suppression, pre-treatment or deuteration of the ionic component. We studied a range of cellulose samples by using various NMR experiments to make an apriori assignment of the cellulose resonances. Chain-end resonances are also visible in the 1HNMR spectrum. This allows the rough determination of the degree of polymerisation (DP) of a sample for low-DP celluloses by the integration of non-reducing chain ends C1 versus polymeric cellobiose C1. Low-DP celluloses show a good agreement with the gel-permeation chromatography (GPC) values, but high-DP pulps show more deviation. For high-purity pulps (pre-hydrolysis kraft and sulfite), residual xyloses and mannoses can also be identified from the 1H-13C heteronuclear single-quantum coherence (HSQC) spectra. Resonances are thus assigned for the common polymeric polysaccharides found in chemical pulps.

Details

Original languageEnglish
Pages (from-to)880-892
Number of pages12
JournalChemSusChem
Volume9
Issue number8
Publication statusPublished - 21 Apr 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • Biomass, Carbohydrates, Ionic liquids, Nmr spectroscopy, Polymerization

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