Abstract
AbstractFor evaluation of changes in phenolic lignin units during kraft
pulping and bleaching, a direct method based on UV reflectance measurements of
pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group
contents were evident when UV reflectance results for isolated lignins and
pulp sheets were compared. This direct method gave reliable results after
alkaline cooking, oxygen delignification, and bleaching stages followed by
alkaline extraction (DE, ZE). However, the phenolic content obtained after
peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced
reactions during pH adjustment of the sheets for measurement concomitant with
ionisation of the phenolic hydroxyl groups. Otherwise, this direct method
based on UV reflectance measurements is a promising new approach for
determining the total content of phenolic lignin units in pulp sheets without
isolating the lignin.
| Original language | English |
|---|---|
| Pages (from-to) | 623-627 |
| Journal | Holzforschung |
| Volume | 61 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2007 |
| MoE publication type | A1 Journal article-refereed |