Condensation reactions of lignin during birch Kraft pulping as studied by thioacidolysis
2004 (English)In: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 30, no 12, 317-322 p.Article in journal (Refereed) Published
The influences of kappa number and ionic strength during birch kraft cooking on the extent of lignin condensation have been studied using thioacidolysis and size exclusion chromatography. Thioacidolysis degrades alkyl-aryl ether bonds in lignin while leaving carbon-carbon and diaryl-ether bonds relatively intact. Therefore, the lignin structures not cleaved during thioacidolysis can be considered as relatively stable and may account,, for example,for the slow residual phase delignification in the kraft cook and for differences in bleachability. It was shown that condensed lignin structures are formed in the residual lignin during birch kraft cooking. The relative amount of such structures increased with decreasing kappa number or with increasing sodium ion concentration in the cook. These structures were also found in a xylan-lignin complex isolated from a birch kraft pulp. The condensed structures were only partly reactive during oxygen delignification.
Place, publisher, year, edition, pages
2004. Vol. 30, no 12, 317-322 p.
bleachability, brightness, cooking, bonds
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-24016ISI: 000227481000001ScopusID: 2-s2.0-25844455214OAI: oai:DiVA.org:kth-24016DiVA: diva2:342715
QC 20100525 QC 201109222010-08-102010-08-102012-03-20Bibliographically approved