Anionic Groups in Papermaking Fibers: Origin, Depth Profile and Surface Distribution
Science Direct Working Paper No S1574-0331(04)70623-2
4 Pages Posted: 7 Jun 2017 Last revised: 13 Jan 2018
Date Written: March 2003
Abstract
The origin and character of anionic groups (AGs) in a broad selection of chemical, mechanical and chemimechanical pulps was investigated using methylene blue sorption (MB) and determination of uronic and hexenuronic acid contents by chromatographic methods. A significant part of AGs in chemical pulps were found be introduced during pulping and bleaching. In case of mechanical and chemimechanical pulps, larger portion of AGs were from uronic acids already present in wood. The amount of AGs on the fiber surfaces was determined by labelling with Mg and MB and subsequent analysis using techniques with different depth resolution, i.e., Xray Photoelectron Spectroscopy (XPS or ESCA) and Energy Dispersive Spectrometry (EDS). Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was also used to study the surface distribution of AGs. Effects of different pulping and bleaching processes on the formation, depth profile and surface distribution of AGs were assessed. The content of AGs for different pulps at proximate depths of 1000 nm and 10 nm varied between 30-60 % and 1-3 % of the total AGs amount, respectively.
Keywords: Macromolecular Chemistry > Cellulose Paper and Textiles, macrochem/0303002
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