| Autor: |
Mun JS; Department of Carbon Materials and Fiber Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea., Mun SP; Department of Wood Science and Technology, Jeonbuk National University, Jeonju 54896, Republic of Korea. |
| Abstrakt: |
The structural and thermal characterization of milled wood lignin (MWL) prepared from bamboo ( Phyllostachys pubescens ) grown in Korea was investigated, and the results were compared with bamboo MWLs from other studies. The C 9 formula of the bamboo MWL was C 9 H 7.76 O 3.23 N 0.02 (OCH 3 ) 1.41 . The Mw and Mn of MWL were 13,000 and 4400 Da, respectively, which resulted in a polydispersity index (PDI) of 3.0. The PDI of the prepared MWL was higher than other bamboo MWLs (1.3-2.2), suggesting a broader molecular weight distribution. The structural features of MWL were elucidated using FT-IR spectroscopy and NMR techniques ( 1 H, 13 C, HSQC, 31 P NMR), which indicate that MWL is of the HGS-type lignin. The major lignin linkages (β-O-4, β-β, β-5) were not different from other bamboo MWLs. The syringyl/guaiacyl ratio, determined from 1 H NMR, was calculated as 0.89. 31 P NMR revealed variations in hydroxyl content, with a higher aliphatic hydroxyl content in MWL compared to other bamboo MWLs. Thermal properties were investigated through TGA, DSC, and pyrolysis-GC/MS spectrometry (Py-GC/MS). The DTG max of MWL under inert conditions was 287 °C, and the T g of MWL was 159 °C. Py-GC/MS at 675 °C revealed a syringyl, guaiacyl, p -hydroxyphenyl composition of 17:37:47. |
