An efficient and mild integration process for the extraction of lignin and preparation of lignopolyol from agricultural waste corn stalk was presented in this study. Firstly, the conditions of the hydrothermal coupled with dilute alkali treatment were optimized to obtain lignin fractions, the structures of which were investigated by high-performance anion-exchange chromatography (HPAEC), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR) and 2D HSQC NMR spectroscopy. Results showed that the optimal condition was hydrothermal reaction at 150 °C for 1 h, and coupled with alkali extraction with 1 M NaOH at 70 °C for 2 h in this study, under which the lignin component with higher yield, better purity and intact lignin structure could be extracted. Subsequently, the obtained high-quality lignin was modified with propylene oxide in the presence of sodium hydroxide under mild conditions, which was characterized by scanning electron microscope (SEM), FT-IR, ³¹P NMR and thermogravimetric analysis. From the optimization results, it was concluded that when the ratio of lignin to propylene oxide was 2:1 mg/mL, the lignopolyol with the largest molecular weight, the most secondary hydroxyl and the best thermal stability could be prepared. This integration process including the isolation of lignin and preparation of lignopolyol from agricultural wastes was conducive to the synthesis of polyurethane materials, and promoted the development of lignin application technology.

本研究提出了一种从农业废弃物玉米秸秆中提取木质素和制备木质素多元醇的高效、温和的整合工艺。首先，优化水热联用稀碱处理条件，得到木质素馏分，通过高效阴离子交换色谱（HPAEC）、凝胶渗透色谱（GPC）、傅里叶变换红外光谱（FT）对其结构进行研究。 -IR) 和 2D HSQC NMR 光谱。结果表明，本研究的最佳条件为150℃水热反应1h，再加上1M NaOH碱提70℃2h，得到的木质素组分收率更高、纯度更好、完整。可以提取木质素结构。随后，³¹ P NMR和热重分析。优化结果表明，当木质素与环氧丙烷的比例为2:1 mg/mL时，可以制备出分子量最大、仲羟基最多、热稳定性最好的木质素多元醇。这种从农业废弃物中分离木质素和制备木质素多元醇的一体化过程有利于聚氨酯材料的合成，促进了木质素应用技术的发展。