Probing the molecular weights of sweetgum and pine kraft lignin fractions, TAPPI Journal June 2021

Application: The molecular weight of lignin fragments in black liquor changes during the kraft cooking process. These changes follow polymeric gel degradation theory. The current work is a step towards specific MW isolation of lignin during the pulping process.

TAPPI conference proceedings and presentations, technical papers, and publication articles provide technical and management data and solutions on topics covering the Pulp, Paper, Tissue, Corrugated Packaging, Flexible Packaging, Nanotechnology and Converting Industries.

Simply select the quantity, add to your cart and your conference paper, presentation or article will be available for immediate download.

Author: uliana M. Jardim, Peter W. Hart, Lucian Lucia, and Hasan Jameel
Probing the molecular weights of sweetgum and pine kraft lig
ABSTRACT: The present investigation undertook a systematic investigation of the molecular weight (MW) of kraft lignins throughout the pulping process to establish a correlation between MW and lignin recovery at different extents of the kraft pulping process. The evaluation of MW is crucial for lignin characterization and utilization, since it is known to influence the kinetics of lignin reactivity and its resultant physico-chemical properties. Sweetgum and pine lignins precipitated from black liquor at different pHs (9.5 and 2.5) and different extents of kraft pulping (30•150 min) were the subject of this effort. Gel permeation chromatography (GPC) was used to determine the number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity of the lignin samples. It was shown that the MW of lignins from both feedstocks follow gel degradation theory; that is, at the onset of the kraft pulping process low molecular weight-lignins were obtained, and as pulping progressed, the molecular weight peaked and subsequently decreased. An important finding was that acetobromination was shown to be a more effective derivatization technique for carbohydrates containing lignins than acetylation, the technique typically used for derivatization of lignin.

New Releases


TAPPI PRESS Catalog eBook 2021

Experience the Power of Publications in the 2021 TAPPI Press Catalog



Kraft Recovery Boilers, Third Edition  

Sponsored by the Recovery Boiler Program R&D Subcommittee of the American Forest & Paper Association (AF&PA) and published by TAPPI Press.



Handbook For Pulp and Paper Technologists (The SMOOK Book), Fourth Edition

The best-selling text to introduce the entire technology of pulp and paper manufacture.



Guidelines for Safe Assessment and Operation of Yankee Dryers  

A project of the Yankee Dryer Safety & Reliability Committee.



Check our newest additions.

TAPPI Press offers some of the most in-depth resources and references for the forest products and related industries. 

See More


Available for Purchase – Conference Proceedings

TAPPI maintains a record of key conference papers, presentations, and other conference publications, available for purchase in a variety of formats.

See More