Table 5 XPS, acetyl, hydrophobicity, and crystallinity index (%) analysis of HPAC-pretreated poplar
Treatment temperature | HPAC concentration (%) | C1 (%) | C2 (%) | C3 (%) | O/C | Acetyl (%) | Hydrophobicity (L/g) | Crystallinity index (%) |
|---|---|---|---|---|---|---|---|---|
AC-pretreated poplar |  | 53.8 | 38.0 | 8.3 | 0.40 | 5.9 ± 0.0 | 0.49 | 55.2 |
60 °C | 40 | 57.1 | 29.1 | 13.7 | 0.40 | 7.6 ± 0.1 | 0.27 | 57.7 |
60 °C | 60 | 53.6 | 33.1 | 13.2 | 0.43 | 8.0 ± 0.0 | 0.14 | 63.0 |
60 °C | 80 | 52.9 | 33.7 | 13.4 | 0.46 | 8.1 ± 0.0 | 0.07 | 64.2 |
40 °C | 100 | 56.1 | 32.5 | 11.4 | 0.44 | 8.1 ± 0.2 | 0.21 | 60.1 |
60 °C | 100 | 52.9 | 36.2 | 11.0 | 0.46 | 8.0 ± 0.2 | 0.06 | 64.9 |
80 °C | 100 | 51.0 | 37.5 | 11.6 | 0.49 | 9.7 ± 0.1 | 0.06 | 68.5 |