Investigating the Effect of Structural Changes of Alkali Lignins Caused by Reduction and Methylation Reaction on the Optical Characteristics of Lignin-Containing Papers

Mirshokraei, Ahmad

doi:10.22092/ijwpr.2010.117260

Document Type : Research Paper

Author

Ahmad Mirshokraei

Professor, Chemistry Department, Payame Noor University, Tehran

https://doi.org/10.22092/ijwpr.2010.117260

Abstract

In this study, changes in optical behavior of poplar Kraft lignin and bagasse Soda lignin, before and after reducing with sodium borohydride and sodium hydrosulfite (dithionite) and also after methylation using dimethyl sulfate, was monitored by measuring optical indices (brightness, k/s, whiteness and Post-Color numbers) of impregnated papers following accelerated thermal aging. The structural changes in lignins caused by reductive reactions, were mostly verified by using absorbance changes (UV-Vis spectrometry) and FI-IR spectroscopy. It was observed that, regarding elimination of chromophoric carbonyl and quinone groups, sodium borohydride showed better and more sustainable performance than sodium hydrosulfite. Therefore, it could be inferred that to improve the brightness of lignin-containing papers and persistance of this brightness, sodium borohydride could exhibit more efficiency and higher applicability.

Keywords

Main Subjects

Chemistry of wood

References

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Iranian Journal of Wood and Paper Science Research

Investigating the Effect of Structural Changes of Alkali Lignins Caused by Reduction and Methylation Reaction on the Optical Characteristics of Lignin-Containing Papers

References

References

Volume 26, Issue 1 - Serial Number 32
March 2011
Pages 10-25

Investigating the Effect of Structural Changes of Alkali Lignins Caused by Reduction and Methylation Reaction on the Optical Characteristics of Lignin-Containing Papers

References

References

Volume 26, Issue 1 - Serial Number 32March 2011Pages 10-25

Volume 26, Issue 1 - Serial Number 32
March 2011
Pages 10-25