Chemical Modification and Improved Hydrophilicity of Lignin Using Phenolation and Amino Alkylation
발표자
()
초록
내용
Lignin as a heterogeneous aromatic biopolymer containing various functional groups was chemically modified by phenolation process and Mannich reaction to achieve an amine-functionalized lignin-based material. Phenolation was carried out using sulfuric acid and phenol as catalyst at lignin/phenol (L/P, wt/wt) ratios of 1/3 and 1/5 to obtain phenolic hydroxyl (Ph-OH) groups on lignin. 31P NMR analysis was used to confirm the completion of the lignin modification. All lignin substructures (β-O-4′, β-5′/α-O-4′, β–β′, α-carbonyl) reacted to incorporate phenol onto their side chains and aromatic nuclei, resulting in a significant decrease in aliphatic hydroxyl groups and an increase in phenolic hydroxyl groups. Amine groups were successfully introduced to the phenolated lignin through the Mannich reaction, confirmed by 1H, 13C NMR, FTIR, and XPS.