Contribution of xylan to the brightness development and stability in the final ECF bleaching of eucalypt (Eucalyptus globulus Labill.) kraft pulp
authors Loureiro, PEG; Sousa, JIT; Graca, M; Carvalho, VS; Evtuguin, DV
nationality International
journal HOLZFORSCHUNG
author keywords bleaching sequences; brightness; chlorine dioxide; Eucalyptus globulus; final bleaching; hydrogen peroxide; pulp; xylan; xylanase
keywords RAMAN-SPECTROSCOPY; HEXENURONIC ACID; CELLULOSIC PULPS; RESIDUAL LIGNIN; CHROMOPHORES; POSTTREATMENT; REVERSION; INDUSTRY; STAGE
abstract Xylans isolated from eucalypt kraft pulps have been characterized by modern analytical methods. The pulps were partially bleached (DEOPD) and fully bleached with either a final ClO2 (DEOPDD) or an alkaline H2O2 (DEOPDP) bleaching stage. Alternatively, xylan isolated from the DEOPD pulp was treated with ClO2 or with H2O2 under the same conditions as pulps in a final bleaching stage and were further characterized. 1 H nuclear magnetic resonance, size exclusion chromatography, UV-vis spectroscopy in cadoxen solution, and UV-resonance Raman spectroscopy were applied as analytical methods. The final ClO2 stage generated new unsaturated moieties in xylan, whereas H2O2 was very effective in the removal of xylan-related chromophores. The role of xylan to the delay of brightness development in the final ClO2 stage was highlighted by means of a pretreatment with xylanase Pulpzyme HC before the final bleaching stage. By this approach, the final bleachability of the pulp was boosted and the brightness stability of the fully bleached pulp was improved.
publisher WALTER DE GRUYTER GMBH
issn 0018-3830
year published 2013
volume 67
issue 5
beginning page 497
ending page 503
digital object identifier (doi) 10.1515/hf-2012-0185
web of science category Forestry; Materials Science, Paper & Wood
subject category Forestry; Materials Science
unique article identifier WOS:000321038000003
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 2.079
5 year journal impact factor 1.807
category normalized journal impact factor percentile 84.686
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg