Table 2. Summary of Chemical, Molecular, and Structural Composition of Technical Lignins.
| K | OS | S | SOX | LS | ECO | |
|---|---|---|---|---|---|---|
| lignin (%) | 96.4a | 98.0a | 98.2a | 63.5a | 80.5b | 72.8b |
| sugars (%) | 1.5 | 0.2 | 2.4 | 2.4 | 3.2b | 17.9b |
| ash (%) | 1.9 | 0.0 | 4.2 | 39.5 | 28.9b | 19.1b |
| Mw (kDa) | 3.7 | 2.1 | 2.5 | 4.8 | 10.5b | 31.4b |
| PD | 2.9 | 1.9 | 2.2 | 2.3 | 5.2 | 4.9 |
| aliphatic −OH (mmol/g) | 1.95 | 1.77 | 1.43 | 1.06 | 3.27b | 5.44b |
| phenolic −OH (mmol/g) | 4.12 | 3.43 | 3.40 | 0.89 | 0.83b | 0.14b |
| –COOH (mmol/g) | 0.49 | 0.12 | 0.96 | 1.28 | 0.74b | 0.40b |
| –OCH3 (%) | 12.48 | 19.60 | 14.27 | 4.23 | 5.56 | 5.84 |
a
Lignin content corresponding to the sum of Klason and acid soluble lignin.
b
Data from Abbadessa et al.35