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On cellulose dissolution and aggregation in aqueous tetrabutylammonium hydroxide

Gubitosi, Marta LU ; Duarte, Hugo; Gentile, Luigi LU ; Olsson, Ulf LU and Medronho, Bruno (2016) In Biomacromolecules 17(9). p.2873-2881
Abstract

Aqueous tetrabutylammonium hydroxide, TBAH(aq), has been found to dissolve cellulose and to be a potential solvent for chemical processing or fiber spinning. In this paper, we have investigated the dissolution state of cellulose in 40 wt % TBAH(aq) solvent, and present an extensive study of rheology, combined with static light and small-angle X-ray scattering, to correlate cellulose aggregation with changes in the rheological parameters. Two cellulose molecular weights are compared. Microcrystalline cellulose (MCC), with a degree of polymerization of ca. 260, and a dissolving pulp with an approximately ten times higher molecular weight. Scattering data demonstrate that cellulose is molecularly dissolved at lower cellulose... (More)

Aqueous tetrabutylammonium hydroxide, TBAH(aq), has been found to dissolve cellulose and to be a potential solvent for chemical processing or fiber spinning. In this paper, we have investigated the dissolution state of cellulose in 40 wt % TBAH(aq) solvent, and present an extensive study of rheology, combined with static light and small-angle X-ray scattering, to correlate cellulose aggregation with changes in the rheological parameters. Two cellulose molecular weights are compared. Microcrystalline cellulose (MCC), with a degree of polymerization of ca. 260, and a dissolving pulp with an approximately ten times higher molecular weight. Scattering data demonstrate that cellulose is molecularly dissolved at lower cellulose concentrations, while aggregates are present when the concentration exceeds a certain value. The onset of the aggregate formation is marked by a pronounced increase in the scattering intensity at low q, shear thinning behavior and violation of the empirical Cox-Merz rule. Additionally, the SAXS data suggest the presence of a solvation shell enriched in TBA+ ions, compared to the bulk solvent. The results are consistent with the recent suggestion that while native cellulose I may still dissolve, solutions are, above a particular concentration, becoming supersaturated with respect to the more stable crystal form cellulose II.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biomacromolecules
volume
17
issue
9
pages
9 pages
publisher
The American Chemical Society
external identifiers
  • scopus:84987740836
  • wos:000383213200011
ISSN
1525-7797
DOI
10.1021/acs.biomac.6b00696
language
English
LU publication?
yes
id
8e8e0fe5-8b74-4127-8439-9329ad821b2c
date added to LUP
2016-11-04 11:57:42
date last changed
2017-10-01 05:25:24
@article{8e8e0fe5-8b74-4127-8439-9329ad821b2c,
  abstract     = {<p>Aqueous tetrabutylammonium hydroxide, TBAH(aq), has been found to dissolve cellulose and to be a potential solvent for chemical processing or fiber spinning. In this paper, we have investigated the dissolution state of cellulose in 40 wt % TBAH(aq) solvent, and present an extensive study of rheology, combined with static light and small-angle X-ray scattering, to correlate cellulose aggregation with changes in the rheological parameters. Two cellulose molecular weights are compared. Microcrystalline cellulose (MCC), with a degree of polymerization of ca. 260, and a dissolving pulp with an approximately ten times higher molecular weight. Scattering data demonstrate that cellulose is molecularly dissolved at lower cellulose concentrations, while aggregates are present when the concentration exceeds a certain value. The onset of the aggregate formation is marked by a pronounced increase in the scattering intensity at low q, shear thinning behavior and violation of the empirical Cox-Merz rule. Additionally, the SAXS data suggest the presence of a solvation shell enriched in TBA<sup>+</sup> ions, compared to the bulk solvent. The results are consistent with the recent suggestion that while native cellulose I may still dissolve, solutions are, above a particular concentration, becoming supersaturated with respect to the more stable crystal form cellulose II.</p>},
  author       = {Gubitosi, Marta and Duarte, Hugo and Gentile, Luigi and Olsson, Ulf and Medronho, Bruno},
  issn         = {1525-7797},
  language     = {eng},
  month        = {09},
  number       = {9},
  pages        = {2873--2881},
  publisher    = {The American Chemical Society},
  series       = {Biomacromolecules},
  title        = {On cellulose dissolution and aggregation in aqueous tetrabutylammonium hydroxide},
  url          = {http://dx.doi.org/10.1021/acs.biomac.6b00696},
  volume       = {17},
  year         = {2016},
}