Jin Huiqi, Shi Haiqiang, Jia Wenchao, Sun Yanning, Sheng Xueru, Guo Yanzhu, Li Haiming, Sun Haidong
Liaoning Key Laboratory of Lignocellulose chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China; Liaoning Collaborative Innovation Center for Lignocellulosic Biorefinery, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
Liaoning Key Laboratory of Lignocellulose chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China; Liaoning Collaborative Innovation Center for Lignocellulosic Biorefinery, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
Int J Biol Macromol. 2022 May 15;207:531-540. doi: 10.1016/j.ijbiomac.2022.03.049. Epub 2022 Mar 13.
The molecular weight is one of the most important factors influencing the utilization of industrial lignin obtained from chemical pulping process. In this paper, a facile operative green solvent system was successfully developed for molecular weight-controllable fractionation of industrial alkali lignin (IAL) at room temperature. The results showed that through adjusting the ratio of water, ethanol and γ-Valerolactone (GVL), the industrial lignin was fractionated into six levels with molecular weight stepwise controllable from low to high. The fractionation is a physical process according to FTIR and 2D-HSQC NMR analysis, and the chemical structure of lignin has not changed. Additionally, the polydispersity of fractionated lignin with higher molecular weight tends to be narrower. The content of hydroxyl and carboxyl group is higher for the fractionated lignin with lower molecular weight, which would be beneficial for the chemical reactivity in the down-stream application.
分子量是影响从化学制浆过程中获得的工业木质素利用的最重要因素之一。本文成功开发了一种操作简便的绿色溶剂体系，用于在室温下对工业碱木质素（IAL）进行分子量可控分级。结果表明，通过调节水、乙醇和γ-戊内酯（GVL）的比例，工业木质素被分级为六个级别，分子量从低到高逐步可控。根据傅里叶变换红外光谱（FTIR）和二维异核单量子相干核磁共振光谱（2D-HSQC NMR）分析，分级过程是一个物理过程，木质素的化学结构没有改变。此外，分子量较高的分级木质素的多分散性趋于变窄。分子量较低的分级木质素中羟基和羧基的含量较高，这将有利于下游应用中的化学反应活性。
