Analytical Pyrolysis Pathways of Guaiacyl Glycerol-β-guaiacyl Ether by Py-GC/MS

Yu Liu, Yu Liu, Gaojin Lyu, Xingxiang Ji, Guihua Yang, Jiachuan Chen, Lucian A. Lucia

Abstract


A synthetic method for obtaining a lignin model compound of β-O-4 structure, guaiacyl glycerol-β-guaiacyl ether, was researched through five reaction steps from guaiacol. The key step of this synthetic method was the condensation reaction between 4-(α-bromoacetyl)-guaiacol (III) and guaiacol (I). The compounds were characterized by 1H nuclear magnetic resonance spectroscopy (1H-NMR) and two-dimensional nuclear magnetic resonance (2D-NMR). Pyrolysis behaviors of guaiacyl glycerol-β-guaiacyl ether were investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The thermal behavior and the evolution profiles of major volatile fragments from the guaiacyl glycerol-β-guaiacyl ether pyrolysis were evaluated. Guaiacol is the major product through Cβ-O homolysis at low temperatures. Cβ-O homolysis and Cβ-O concerted decomposition occurred at moderate temperatures, producing guaiacol, 2-hydroxybenzaldehyde, 2-methoxybenzaldehyde, and various phenolic compounds. At high temperatures, the products obtained from Cβ-O homolysis and Cβ-O concerted decomposition experienced secondary thermal cracking, generating a large number of small molecule products, which increased the complexity of the pyrolytic products.

Keywords


Pyrolysis; Lignin model compound; 2D-NMR; Py-GC/MS; TG

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126