Brightness stability of eucalyptus-dissolving pulps: effect of the bleaching sequence

Tutkimustuotos: Lehtiartikkeli


  • Jordan Perrin
  • Dominique Lachenal
  • Christine Chirat


  • Grenoble INP Pagora


The factors governing the brightness reversion (BR) of dissolving pulps under heat exposure are investigated. Carbonyl (CO) groups were artificially introduced on fully bleached pulp by sodium hypochlorite (NaClO) oxidation. It was demonstrated that the CO groups are responsible for loss of brightness stability (BS). These groups were partly eliminated by an alkaline extraction stage (E), which improved BS. However, an alkaline peroxide stage (P) was more efficient than E to improve BS, but without any additional CO loss. Moreover, an unbleached dissolving pulp was bleached in the laboratory by elemental chlorine free (ECF) and totally chlorine free (TCF) [ozone-based] sequences to the same brightness. The very low CO content was about the same in both cases. The ECF-bleached pulp showed substantially lower BS than the TCF pulp. These results are interpreted such that the chemistry of chromophores in the unbleached pulp also governs BS. In situ detection of phenolic and quinone chromophores in bleached dissolving pulp was performed by electron paramagnetic resonance (EPR) spectroscopy and ultraviolet resonance Raman (UVRR) spectroscopy. The content of these groups was bleaching-sequence-dependent, which may be related to the BS differences.


TilaJulkaistu - heinäkuuta 2017
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu
TapahtumaEuropean Workshop on Lignocellulosics and Pulp - Autrans, Ranska
Kesto: 28 kesäkuuta 201630 kesäkuuta 2016
Konferenssinumero: 14

ID: 14527938