1. The effect of bleaching on the surface chemistry of mechanical pulps
- Subjects
Fibers ,Chemistry ,Mechanical pulps ,genetic structures ,Peroxide bleaching ,Surface properties ,Bleaching ,Fines ,sense organs ,skin and connective tissue diseases ,Analysis - Abstract
The aim of this work was to obtain knowledge on how peroxide bleaching anddithionite bleaching change the surface chemistry of mechanical pulps, as well as of isolated fibres and fines, by using chemical analysis in combination with two surface-sensitive spectroscopic methods, ESCA (Electron Spectroscopy for Chemical Analysis) and ToF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry). The changes in the surface chemistry induced by bleaching depended on the bleaching chemical, pulp type and pulp fraction. Peroxide bleaching resulted in greater changes in the surface chemistry than dithionite. Peroxide bleaching removed extractives more effectively from CTMP than from TMP, but changes were less obvious for CTMP fines than for TMP fines. The surface of fibrils, in particular, was changed during bleaching due to removal or deposition of extractives. Fibres and flakes underwent similar changes in their surface chemistry. ToF-SIMS and ESCA gave complementary information about the surface chemistry of mechanical pulps and pulp fractions.
- Published
- 2008