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

High‐molecular‐weight celluloses (which even include bacterial cellulose) can be dissolved fully in methyltrioctylphosphonium acetate/[D 6 ]DMSO solutions to allow the measurement of resonance‐overlap‐free 1 D and 2 D 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 a priori assignment of the cellulose resonances. Chain‐end resonances are also visible in the 1 H NMR 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 1 H– 13 C heteronuclear single‐quantum coherence (HSQC) spectra. Resonances are thus assigned for the common polymeric polysaccharides found in chemical pulps.