Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea.
Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea.
Bioresour Technol. 2024 Dec;413:131500. doi: 10.1016/j.biortech.2024.131500. Epub 2024 Sep 18.
As millions of tons of kraft lignin are being wasted, a potential application is to use its crosslinking reactions to build thermosetting bio adhesives. However, the crosslinking reactions between lignin molecules are not fully understood. The present study aims to elucidate the crosslinking reactions of the model lignin compound guaiacylglycerol-β-guaiacyl ether (GGE) via one-step hydroxymethylation/ amination with formaldehyde and diethylenetriamine (DETAM), or one-step glyoxylation/ amination with glyoxal and DETAM via liquid NMR techniques such as H NMR, C NMR, 2D H-C, and H-N HSQC NMR. Specifically, the 2D H-C HSQC NMR spectra confirm the presence of -CH-NH- with a chemical shift of H 2.6-3.6/C 40-60 ppm, and the formation of methylene linkages via the crosslinking reaction. Also, the 2D H-N HSQC NMR spectra clearly detect the formation of amide and imine bonds at H 7.8/N 110 and H 8.07/N 121.5 ppm from the crosslinked GGE.
当数百万吨的 kraft 木质素被浪费时，一个潜在的应用是利用其交联反应来构建热固性生物胶。然而，木质素分子之间的交联反应还不完全清楚。本研究旨在通过一步羟甲基化/胺化与甲醛和二乙烯三胺（DETAM），或一步乙二醛/胺化与乙二醛和 DETAM，利用液体 NMR 技术如 H NMR、C NMR、2D H-C 和 H-N HSQC NMR 来阐明模型木质素化合物愈创木基甘油-β-愈创木基醚（GGE）的交联反应。具体来说，2D H-C HSQC NMR 谱证实了-CH-NH-的存在，其化学位移为 H 2.6-3.6/C 40-60 ppm，并且通过交联反应形成亚甲基键。此外，2D H-N HSQC NMR 谱清楚地检测到交联 GGE 中酰胺和亚胺键在 H 7.8/N 110 和 H 8.07/N 121.5 ppm 处的形成。
