Abstract
Abstract The degradation of lignin can generate a variety of products with diverse applications. Lignin is abundant on earth; however, its high molecular weight and stable properties impede its development. Currently, acid-catalyzed degradation of lignin is a relatively common and promising catalytic method, particularly DES catalytic degradation, which is not only environmentally friendly but also features an excellent degradation effect. This report discusses the degradation mechanism and effect of the formic acid-choline chloride DES system for the degradation of alkaline lignin. According to fourier transform infrared spectroscopy (FTIR) and 1H-NMR spectroscopy, it is evident that the phenolic hydroxyl content of lignin increases after degradation, which indicates the cleavage of β-O-4′ ether bonds in the macromolecular structure. Gel permeation chromatography (GPC) was employed to determine the molecular weight of degraded lignin, and regenerated lignin with low molecular weight and low dispersibility was obtained. The minimum average molecular weight (M w ) was 2.3 × 103 g/mol. During the depolymerization process, it was also discovered that the repolymerization and degradation reactions formed a competitive relationship. The lignin oil contained primarily propanoic acid ethyl ester, acetic acid butyl ester, 2-methoxy-4-propyl phenol, 2-methoxy phenol, and apocynin, as determined by GC-MS.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.