Influence of urea on methyl β -D-glucopyranoside in alkali at different temperatures
Artikel i vetenskaplig tidskrift, 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.

NaOH

Cellulose

NMR

Dissolution

Urea

Methyl β -D-glucopyranoside

Författare

Maria Gunnarsson

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk reaktionsteknik

Merima Hasani

Wallenberg Wood Science Center (WWSC)

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk reaktionsteknik

Diana Bernin

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Cellulose

0969-0239 (ISSN)

Vol. 26 18 9413-9422

Ämneskategorier

Fysikalisk kemi

Annan kemiteknik

Annan kemi

DOI

10.1007/s10570-019-02730-4

Mer information

Senast uppdaterat

2019-12-03