Influence of urea on methyl β -D-glucopyranoside in alkali at different temperatures
Journal article, 2019

The dissolution efficiency plays an important role on the properties of regenerated cellulose-based products. Urea is known to be one of the additives aiding to improve cellulose dissolution in the NaOH(aq) system. The acting mechanism caused by urea has been debated and one of the hypothesis is that urea could induce a conformational change on cellulose, which promotes dissolution. Here we used NMR spectroscopy on a model system for cellulose, namely, methyl β -D-glucopyranoside (β -MeO-Glcp) and compared chemical shifts and J couplings, which both are indicators for conformational changes, as a function of temperature and upon the addition of urea. We found that in NaOH(aq), the hydroxymethyl group changes its conformation in favour of the population of the gt rotamer, while the presence of urea induced temperature dependent conformational changes. Heteronuclear Overhauser effect experiments showed that urea associates with cellulose but in a non-specific manner. This suggests that urea rather than binding to the carbohydrate, changes the chemical environment inducing a change in conformation of β -MeO-Glcp and likely also for cellulose when dissolved in NaOH(aq) with urea.

Dissolution

NMR

NaOH

Urea

Cellulose

Methyl β -D-glucopyranoside

Author

Maria Gunnarsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

Merima Hasani

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

Wallenberg Wood Science Center (WWSC)

Diana Bernin

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Process and Reaction Engineering

Cellulose

0969-0239 (ISSN)

Vol. 26 18 9413-9422

Subject Categories

Physical Chemistry

Other Chemical Engineering

Other Chemistry Topics

DOI

10.1007/s10570-019-02730-4

More information

Latest update

2/15/2021