Audu Idi Guga, Brosse Nicolas, Winter Heiko, Hoffmann Anton, Bremer Martina, Fischer Steffen, Laborie Marie-Pierre
Chair of Forest Biomaterials, University of Freiburg, Werthmannstr. 6, 79085 Freiburg im Breisgau, Germany.
Laboratoire d'Étude et de Recherche sur le Matériau Bois LERMAB, Faculty of Science and Technology, University of Lorraine, Boulevard des Aiguillettes, BP 70239, 54506 Vandœuvre lès Nancy CEDEX, France.
Polymers (Basel). 2018 Jun 5;10(6):619. doi: 10.3390/polym10060619.
During biomass fractionation, any native acetylation of lignin and heteropolysaccharide may affect the process and the resulting lignin structure. In this study, (TC) and its lignin isolated by milling (MWL), ionosolv (ILL) and organosolv (EOL) methods were investigated for acetyl group content using FT-Raman, ¹H NMR, 2D-NMR, back-titration, and Zemplén transesterification analytical methods. The study revealed that TC is a highly acetylated grass; extractive free TC (TC) and TC MWL exhibited similar values of acetyl content: 6 wt % and 8 wt % by Zemplén transesterification, respectively, and 11 wt % by back-titration. In contrast, lignin extracted from organosolv and [EMIm][OAc] pulping lost 80% of the original acetyl groups. With a high acetyl content in the natural state, TC could be an interesting raw material in biorefinery in which acetic acid could become an important by-product.
在生物质分级过程中，木质素和杂多糖的任何天然乙酰化作用都可能影响该过程以及所得木质素的结构。在本研究中，使用傅里叶变换拉曼光谱（FT-Raman）、¹H核磁共振（¹H NMR）、二维核磁共振（2D-NMR）、返滴定法和泽姆普伦酯交换分析法，对（TC）及其通过研磨法（MWL）、离子液体法（ILL）和有机溶剂法（EOL）分离得到的木质素的乙酰基含量进行了研究。研究表明，TC是一种高度乙酰化的草类；脱除提取物的TC（TC）和TC MWL的乙酰含量值相似：通过泽姆普伦酯交换法分别为6 wt%和8 wt%，通过返滴定法为11 wt%。相比之下，从有机溶剂法和[EMIm][OAc]制浆法提取的木质素损失了80%的原始乙酰基。由于TC在天然状态下具有较高的乙酰含量，它可能是生物炼制中一种有趣的原料，在生物炼制中乙酸可能成为一种重要的副产物。
