Yimtrakarn Trakarn, Kaveevivitchai Watchareeya, Lee Wen-Chien, Lerkkasemsan Nuttapol
Department of Chemical Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Ladkrabang, Bangkok 10520, Thailand.
Department of Chemical Engineering, National Cheng Kung University, Tainan City 70101, Taiwan.
Polymers (Basel). 2022 Feb 20;14(4):814. doi: 10.3390/polym14040814.
Lignin is the most abundant natural aromatic polymer, especially in plant biomass. Lignin-derived phenolic compounds can be processed into high-value liquid fuel. This study aimed to determine the yield of lignin by the microwave-assisted solvent extraction method and to characterize some essential properties of the extracted lignin. Rubberwood sawdust () was extracted for lignin with an organic-based solvent, either ethanol or isopropanol, in a microwave oven operating at 2450 MHz. Two levels of power of microwave, 100 W and 200 W, were tested as well as five extraction times (5, 10, 15, 20, 25, and 30 min). The extracted lignin was characterized by Klason lignin, Fourier transform infrared spectroscopy (FT-IR), 2D HSQC NMR, Ultraviolet-visible spectrophotometry (UV-vis), and Bomb calorimeter. The results showed that the yield of extracted lignin increased with the extraction time and power of the microwave. In addition, the extraction yield with ethanol was higher than the yield with isopropanol. The highest yield was 6.26 wt.%, with ethanol, 30 min extraction time, and 200 W microwave power.
木质素是最丰富的天然芳香族聚合物，尤其是在植物生物质中。木质素衍生的酚类化合物可加工成高价值的液体燃料。本研究旨在通过微波辅助溶剂萃取法测定木质素的产率，并对提取的木质素的一些基本性质进行表征。用乙醇或异丙醇等有机基溶剂在2450 MHz的微波炉中从橡胶木屑中提取木质素。测试了100 W和200 W两个微波功率水平以及五个提取时间（5、10、15、20、25和30分钟）。通过克拉斯森木质素、傅里叶变换红外光谱（FT-IR）、二维异核单量子相干核磁共振（2D HSQC NMR）、紫外可见分光光度法（UV-vis）和弹式量热计对提取的木质素进行表征。结果表明，提取的木质素产率随提取时间和微波功率的增加而增加。此外，乙醇的提取产率高于异丙醇。最高产率为6.26 wt.%，采用乙醇、30分钟提取时间和200 W微波功率。
