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Journal articles
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On the nominal transverse shear strai to characterize the severity of creasing, TAPPI JOURNAL April 2018

On the nominal transverse shear strai to characterize the severity of creasing, TAPPI JOURNAL April 2018

Journal articles
Magazine articles
Open Access
Enzymatic treated viscose fibers functionalized by chitosan, TAPPI JOURNAL August 2018

Enzymatic treated viscose fibers functionalized by chitosan, TAPPI JOURNAL August 2018

Journal articles
Magazine articles
Open Access
Effect of pulper consistency on stickies size distribution, TAPPI JOURNAL August 2018

Effect of pulper consistency on stickies size distribution, TAPPI JOURNAL August 2018

Journal articles
Open Access
Acoustic analysis of recovery boiler dissolving tank operati

Acoustic analysis of recovery boiler dissolving tank operation and smelt shattering efficiency, TAPPI JOURNAL September 2016

Journal articles
Magazine articles
Open Access
Recent advances in lignin-based polyurethanes, TAPPI JOURNAL

Recent advances in lignin-based polyurethanes, TAPPI JOURNAL April 2017

Journal articles
Magazine articles
Open Access
Modeling the influence of forming fabric structure on vacuum

Modeling the influence of forming fabric structure on vacuum box dewatering, TAPPI JOURNAL August 2017

Journal articles
Magazine articles
Open Access
Oil absorption and desorption by polypropylene fibers, TAPPI

Oil absorption and desorption by polypropylene fibers, TAPPI JOURNAL September 2017

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

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.

Journal articles
Magazine articles
Open Access
Soybean peroxidase treatment of ultra-high kappa softwood pulp to enhance yield and physical properties, TAPPI Journal September 2020

ABSTRACT: The working hypothesis serving as basis for this study is that pulping to a higher kappa number will produce a higher yield pulp, and then treating that pulp with a surface reactive lignin peroxidase to ablate surface lignin will increase specific bonding area. In the present case, the working hypothesis was modified so that soybean peroxidase (SBP) works like lignin peroxidase to modify surface lignin on high-kappa, high-yield softwood pulps to facilitate enhanced fiber-to-fiber bonding such that the resulting paper strength is similar to the lower kappa soft-wood pulp generally used to make linerboard. Soybean peroxidase is actually a plant peroxidase that exhibits lignin peroxidase-like activity. It is not a lignin peroxidase derived from white rot fungus. The current work did show a significant improvement in pulp yield (62.2% vs. 55.2% yield for a 103-kappa control linerboard grade sheet), while treatment with SBP showed that tensile, burst, and STFI properties of the pulp were improved, although more convincing data needs to be obtained.

Journal articles
Magazine articles
Open Access
Lignin carbohydrate complex studies during kraft pulping for producing paper grade pulp from birch, TAPPI Journal September 2020

ABSTRACT: Paper grade pulp production across the globe is dominated by the kraft process using different lignocellulosic raw materials. Delignification is achieved around 90% using different chemical treatments. A bottleneck for complete delignification is the presence of residual covalent bonds that prevail between lignin and carbohydrate even after severe chemical pulping and oxygen delignification steps. Different covalent bonds are present in native wood that sustain drastic pulping conditions. In this study, 100% birch wood was used for producing paper grade pulp, and the lignin carbohydrate bonds were analyzed at different stages of the kraft cook. The lignin carbohydrate bonds that were responsible for residual lignin retention in unbleached pulp were compared and analyzed with the original lignin-carbohydrate complex (LCC) bonds in native birch wood. It was shown that lignin remaining after pulping and oxygen delignification was mainly bound to xylan, whereas the lignin bound to glucomannan was for the most part degraded.