Research on FTIR Analysis of Populus nigra L. Lignin Structure Changes in Different Bleaching Processes

Abstract:

To study the bleaching mechanisms of H₂O₂ bleaching, H₂O₂ displacement bleaching and H₂O₂ /TAED bleaching, three kinds of lignin bleached with above processes were obtained. Three types of treated Populus nigra L lignins structure were identified and the functional groups were quantitied by FTIR. In contrast, the deacetylation and the breakage of ester bonds in H₂O₂/TAED bleaching system was much more significant. The total carbonyl group of H₂O₂ bleached lignin decreased 6.6% while displacement bleached lignin and H₂O₂/TAED bleached lignin decreased 9.2% and 15.8% respectively. The PT bleaching process had stronger oxidability to destroy the syringyl units in lignin. The breakage of ether bonds and alcoholic hydroxyl dehydration in side chain increased after bleaching. In contrast, the stronger destroyed effection on guaiacyl dialkyl ether bond with PT bleaching processes. The conclusions obtained may interpret H₂O₂ displacement bleaching and H₂O₂/TAED bleaching systems have better bleaching efficiency than H₂O₂ bleaching system.

• Periodical: Advanced Materials Research (Volumes 236-238)
• Pages: 1283-1287
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.236-238.1283
• Online since: May 2011
• Authors: Qiang Zhao, De Zhi Sun, Jun Wen Pu, Xiao Juan Jin, Mian Xing
• Keywords: FT-IR, Lignin Structure, Populus Nigra L

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