Oxidation of residual lignin with alkaline hydrogen peroxide. Part II: Elimination of chromophoric groups
2001 (English)In: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 27, no 7, 244-248 p.Article in journal (Refereed) Published
Isolated residual lignin from art oxygen-bleached kraft pulp was subjected to oxidation with alkaline hydrogen peroxide under different time and temperature conditions in both the absence and presence of stabilizing agents and transition metal ions. The resulting lignin samples were analyzed by UV/VIS and FTIR spectroscopy. The analyses demonstrate the occurrence at a temperature as low as 50 degreesC: of a rapid but limited elimination of chromophoric groups, resulting in the formation of carboxyl groups. The presence of DTPA and magnesium ions stabilizes the hydrogen peroxide towards decomposition and the chromophore elimination is improved. At a higher oxidation temperature, 80 degreesC, the effect of added stabilizer(s) is particularly pronounced. Addition of transition metal ions resulted in a rapid decomposition of hydrogen peroxide and the introduction of new chromophoric groups.
Place, publisher, year, edition, pages
2001. Vol. 27, no 7, 244-248 p.
oxidation, lignins, hydrogen peroxide, kraft pulps, bleached pulps, oxygen bleaching, transition metals, ions, stabilizers, temperature, reaction time, chromophores
IdentifiersURN: urn:nbn:se:kth:diva-20809ISI: 000169946000005OAI: oai:DiVA.org:kth-20809DiVA: diva2:339506
QC 201005252010-08-102010-08-10Bibliographically approved