State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510641, China.
Bioresour Technol. 2010 Apr;101(7):2311-6. doi: 10.1016/j.biortech.2009.11.037. Epub 2009 Dec 9.
There is a commercial need to increase the amount of industrial produced lignin. An 86.24 wt.% formic acid solution with 0.2M H(2)SO(4) as the catalyst was used to isolate the lignin of dewaxed wheat straw at different residence times and reaction temperatures. Lignin was extracted and purified separately from hydrolysates and residual solids after treatment. The lignin obtained has been characterized by FTIR (Fourier transform infrared), GPC (Gel permeation chromatography), and (1)H NMR (Nuclear magnetic resonance). Results from these analyses indicated that oxidative cleavage of bonds in the lignin macromolecule has occurred during the formic acid treatment, leading to formation of oligomers of lignin with lower molecular weight. Moreover, it was found that guaiacyl unit is the main structure, the content of syringyl unit is higher than that of the hydroxybenzyl unit and beta-O-4 together with beta-5 ether bonds is also identified in the molecular structure of lignin of wheat straw obtained from the formic acid process.
市场需要增加工业生产的木质素的数量。采用 86.24wt%甲酸溶液，以 0.2M H(2)SO(4)为催化剂，从不同停留时间和反应温度下脱蜡麦秸中分离木质素。木质素分别从水解产物和处理后的残余固体中提取和纯化。通过 FTIR（傅里叶变换红外光谱）、GPC（凝胶渗透色谱）和（1）H NMR（核磁共振）对获得的木质素进行了表征。这些分析结果表明，在甲酸处理过程中，木质素大分子中的键发生了氧化裂解，导致木质素低分子量的低聚物的形成。此外，还发现愈创木基单元是主要结构，丁香基单元的含量高于羟甲基单元，并且在从甲酸法获得的麦秸木质素的分子结构中也鉴定了β-O-4 与β-5 醚键的结合。
