Table 2. Effect of the Process Conditions on the Sulfur Content in the DEAE-Cellulose Sulfate during Sulfation with Sulfamic Acid in the Presence of Urea at 90 °C.
sulfur
content (wt %) |
||
---|---|---|
time (h) | 1,4-dioxane | deep eutectic solvent (SAA/U) |
0.5 | 2.3 | 2.0 |
1 | 3.8 | 3.1 |
1.5 | 6.9 | 4.9 |
2 | 8.5 | 6.4 |
3 | 10.1 | 8.9 |
4 | 10.2 | 9.2 |