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Published on: October 4, 2019
Direct characterization of hydrogen peroxide bleached thermomechanical pulp using spectroscopic methods
Adam Wójciak1, Henryk Kasprzyk, Igor Khmelinskii
1Institute of Chemical Wood Technology and Chair of Chemistry, Agricultural University of Poznań, 60-623 Poznań, Poland.
The Journal of Physical Chemistry. A
|October 5, 2007
Summary
Hydrogen peroxide bleaching of thermomechanical pulp (TMP) was analyzed using spectroscopy. This study elucidates the chemical changes in pulp fibers and bleaching solutions, revealing insights into the peroxide treatment process.
Area of Science:
- Pulp and Paper Chemistry
- Wood Chemistry
- Spectroscopic Analysis
Background:
- Thermomechanical pulp (TMP) bleaching is crucial for paper production.
- Hydrogen peroxide is a common bleaching agent, but its chemical interactions require detailed study.
- Understanding the chemistry of peroxide bleaching is essential for optimizing pulp quality and environmental impact.
Purpose of the Study:
- To investigate the effects of hydrogen peroxide bleaching on TMP under acidic and alkaline conditions.
- To elucidate the chemical mechanisms involved in peroxide bleaching using various spectroscopic methods.
- To analyze changes in pulp composition and surface chemistry.
Main Methods:
- Spectroscopic analytical methods were employed.
- Hydroxyl radical determination in bleaching solutions.
- Analysis of carbonyl and carboxyl groups in pulp.
- X-ray photoelectron spectroscopy (XPS) for cellulose fiber surface analysis.
- Diffuse reflectance laser flash photolysis (DRLFP).
- Fourier transform infrared (FTIR) spectroscopy.
- FT-Raman spectroscopy.
Main Results:
- Spectroscopic analyses elucidated the chemistry of hydrogen peroxide treatment.
- DRLFP revealed photochemical behavior changes after acidic peroxide bleaching.
- FTIR confirmed the non-delignifying nature of the bleaching process.
- Two-stage peroxide bleaching with catalysts/stabilizers suppressed carbonyl and formed carboxyl groups.
- FT-Raman showed removal of coniferaldehyde groups under both acidic and alkaline conditions.
Conclusions:
- Hydrogen peroxide bleaching of TMP involves complex chemical transformations.
- The study provides a detailed spectroscopic understanding of peroxide bleaching chemistry.
- Optimized bleaching conditions can be developed based on these findings.
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