Jiang Xiao, Tian Zhongjian, Ji Xingxiang, Ma Hao, Yang Guihua, He Ming, Dai Lin, Xu Ting, Si Chuanling
State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), 3501 Daxue Road, Jinan 250353, China; Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), 3501 Daxue Road, Jinan 250353, China; Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Int J Biol Macromol. 2022 Mar 15;201:400-410. doi: 10.1016/j.ijbiomac.2021.12.162. Epub 2022 Jan 4.
The application of industrial kraft lignin is limited by its low molecular weight, dark color, and low solubility. In this work, an efficient crosslinking reaction with N,N-Dimethylformamide (DMF) and 1,6-dibromohexane was proposed for adjusting the molecular weight and color of lignin. The chemical structure of alkylation lignin was systematically investigated by gel permeation chromatography (GPC), ultraviolet spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and 2D heteronuclear single quantum correlation nuclear magnetic resonance (HSQC NMR) spectra. After the alkylation modification, the molecular weights of the lignin were increased to 1643%. The resinol (β-β), β-aryl ether (β-O-4), and phenylcoumaran (β-5) linkages were still the main types of the linkages. The formation of β-β linkage would be inhibited at high temperatures. The color reduction of lignin can be attributed to the low content of chromophores and low packing density. This alkylation lignin will be a new and general approach for developing molecular weight-controlled and light-colored lignins, which can find more applications in cosmetics, packing, and other fields.
工业硫酸盐木质素的应用受到其低分子量、深色和低溶解度的限制。在这项工作中，提出了一种与N，N-二甲基甲酰胺（DMF）和1，6-二溴己烷的有效交联反应，用于调节木质素的分子量和颜色。通过凝胶渗透色谱（GPC）、紫外光谱、傅里叶变换红外（FT-IR）光谱和二维异核单量子相关核磁共振（HSQC NMR）光谱对烷基化木质素的化学结构进行了系统研究。烷基化改性后，木质素的分子量增加到1643%。树脂醇（β-β）、β-芳基醚（β-O-4）和苯基香豆满（β-5）键仍然是主要的键类型。在高温下，β-β键的形成会受到抑制。木质素的颜色降低可归因于发色团含量低和堆积密度低。这种烷基化木质素将成为开发分子量可控和浅色木质素的一种新的通用方法，可在化妆品、包装和其他领域找到更多应用。
