Aqueous N,N-dimethylmorpholinium hydroxide as a novel solvent for cellulose

Abstract N,N-dimethylmorpholinium hydroxide was synthesized and its ability to dissolve microcrystalline cellulose and pulp was assessed for the first time. Microscopy and UV–Vis measurements showed that dissolution occurred over a range of 1–2 M concentration of the solvent and a maximum solubility of 7 wt% microcrystalline cellulose could be achieved. The stability of cellulose solutions was evaluated by size exclusion chromatography, which did not detect degradation to any noticeable extent. This observation was further confirmed by 13C NMR measurements. Finally, DLS studies confirmed that most of the cellulose was molecularly dissolved, with intrinsic viscosity values indicating cellulose chains expansion in this solvent.