1. Tetrabutyl ammonium acetate as a solvent for cellulose
Alexander Idström

2. New sustainable solvent systems for the next generation regenerated cellulose textile fibers based on Swedish forest resources

3. Quaternary ammonium salts
New sustainable solvent systems for the next generation regenerated cellulose textile fibers based on Swedish forest resources
Quaternary ammonium salts
[TBA]F
[TBA]OH
[TBA]Ac
Good cellulose solvents!

4. MCC Dissolving pulp TBAA in DMSO Light microscopy 1H and 13C NMR
Diffusion NMR
MD simulations
DFT calculations

5. 1:8
2:7
3:6

6. A dissolution limit appear around 1:1 molar ratio AGU/TBAA

7. MD simulations 2:7 TBAA/DMSO with 10% cellulose
Transient, though sometimes longlived, contacts between cellulose chains but no trend towards a greater degree of aggregation with time, were observed.
Acetate ions bound to the cellulose hydroxyl groups to such an extent that a majority of the acetate ions were associated to cellulose chains at any given time.
The TBA cations seems to primarily reside in the space between cellulose chains.

8. Changes in chemical shift

9. Changes in chemical shift
1H NMR spectroscopy was used to follow the chemical shifts of the components of the IL with increasing cellulose concentration, as seen in Figure 7. This method has previously been used to determine changes in the hydrogen bond pattern in ILs (Hall et al., 2012)
Ökat shift -> deshielded, färre elektroner
Minskat shift -> shielded, fler elektroner
An increase of the chemical shift of the acetate ion could be seen with increasing amount of added cellulose. For the EMIMAc system, this has previously been explained by increasing amount of hydrogen bonds between cellulose and the acetate ion, with increasing cellulose content (Ries et al., 2014). A corresponding decrease in the chemical shift of the hydrogen closest to the nitrogen in the TBA could also be seen. For the other hydrogens in the TBA chains only a small change in the chemical shift could be noticed.
A decrease of the chemical shift of the DMSO hydrogen could also be seen with increasing amount of added cellulose. If this is an indication that DMSO is contributing to the dissolution of cellulose in the TBAA/DMSO system or if this is an effect of the change in the solvent matrix with added cellulose is to be investigated further.

10. Changes in chemical shift
1H NMR spectroscopy was used to follow the chemical shifts of the components of the IL with increasing cellulose concentration, as seen in Figure 7. This method has previously been used to determine changes in the hydrogen bond pattern in ILs (Hall et al., 2012)
Ökat shift -> deshielded, färre elektroner
Minskat shift -> shielded, fler elektroner
An increase of the chemical shift of the acetate ion could be seen with increasing amount of added cellulose. For the EMIMAc system, this has previously been explained by increasing amount of hydrogen bonds between cellulose and the acetate ion, with increasing cellulose content (Ries et al., 2014). A corresponding decrease in the chemical shift of the hydrogen closest to the nitrogen in the TBA could also be seen. For the other hydrogens in the TBA chains only a small change in the chemical shift could be noticed.
A decrease of the chemical shift of the DMSO hydrogen could also be seen with increasing amount of added cellulose. If this is an indication that DMSO is contributing to the dissolution of cellulose in the TBAA/DMSO system or if this is an effect of the change in the solvent matrix with added cellulose is to be investigated further.

11. Changes in chemical shift
1H NMR spectroscopy was used to follow the chemical shifts of the components of the IL with increasing cellulose concentration, as seen in Figure 7. This method has previously been used to determine changes in the hydrogen bond pattern in ILs (Hall et al., 2012)
Ökat shift -> deshielded, färre elektroner
Minskat shift -> shielded, fler elektroner
An increase of the chemical shift of the acetate ion could be seen with increasing amount of added cellulose. For the EMIMAc system, this has previously been explained by increasing amount of hydrogen bonds between cellulose and the acetate ion, with increasing cellulose content (Ries et al., 2014). A corresponding decrease in the chemical shift of the hydrogen closest to the nitrogen in the TBA could also be seen. For the other hydrogens in the TBA chains only a small change in the chemical shift could be noticed.
A decrease of the chemical shift of the DMSO hydrogen could also be seen with increasing amount of added cellulose. If this is an indication that DMSO is contributing to the dissolution of cellulose in the TBAA/DMSO system or if this is an effect of the change in the solvent matrix with added cellulose is to be investigated further.
Effects of hydrogen bonding between the acetate and cellulose could be seen

12. 1H:
1H:
The chemical shift of acetate is dependent on the molar ratio AGU/acetate

13. Diffusion 2:7 From simulations Ev inte visa?..
Absolute diffusion rates
Gröna trianglar är combined diffusion rate for III and V, making an abrovinch comparing the combined diffrate with the diffrate for I, II and IV gives V. Due to the overlap, for high cellulose concentrations the results are a bit hard to analyze…

14. Conclusions
A clear dissolution limit could be found around the molar ratio 1:1 TBAA/AGU, for all used solvents.
Effects of hydrogen bonding between the acetate and cellulose could be seen.
TBA is electrostatically bound to the acetate.

15. Tobias Köhnke, Carina Olsson
Ulf Olsson, Marta Gubitosi, Luigi Gentile, Mikael Lund, Erik Wernersson, Björn Stenqvist
Caroline Löfgren

16. Scientific Work for Industrial Use www.swerea.se