Kraft pulp hornification: A closer look at the preventive effect gained by glucuronoxylan adsorption

Köhnke, Tobias; Lund, Kristoffer; Brelid, Harald; Westman, Gunnar

doi:10.1016/j.carbpol.2010.02.023

Cited by 74 publications

(45 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The measurements have shown that the WRV of an un-opened cotton boll (never-dried) was 1.4 g/g, whereas the WRV of fielddried cotton was 0.46 g/g. For comparison, the WRV of never-dried Kraft pulp has been reported to drop from 1.5 to 1.0 g/g when subjected to one drying and rewetting cycle (Köhnke et al 2010). The decrease in the WRV of cotton during the initial drying is, thus, much larger in cotton compared to pulp.…”

Section: Resultsmentioning

confidence: 99%

“…In order to avoid hornification during the drying of the samples, a solvent exchange was performed to replace water with cyclohexane. This was done through a solvent exchange procedure in which the water was initially replaced with dry acetone, and then the dry acetone was replaced with cyclohexane (Köhnke et al 2010;Wang et al 2003). After the solvent exchange, the samples were dried in a nitrogen stream overnight.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Chemical and ultrastructural changes in cotton cellulose induced by laundering and textile use

et al. 2014

Self Cite

View full text Add to dashboard Cite

The textile industry is currently under pressure to decrease environmental load related to both the manufacture and the use of textiles. Material recycling may be one of many ways to accomplish such a decrease. Age-induced property changes in cotton textiles are important to understand in order to facilitate the recycling of cotton textiles. Consequently, this study investigates ultrastructural and chemical changes that take place in the cellulose of cotton sheets over a long time period of use and laundering. Ultrastructural changes were studied using water retention value (WRV), specific surface area measurement, scanning electron microscopy and solid state NMR spectroscopy. Chemical changes through measurement of intrinsic viscosity with and without reductive treatment, molecular mass distribution and carboxylate group content. A substantial decrease in mass average molecular mass from 1,320 to 151 kDa was observed when subjecting the sheets to more than 50 launderings. In contrast, only small differences in WRV, in fibril dimensions and crystallinity estimated using solid state NMR spectra, were observed between sheets laundered 2-4 times and more than 50 times. On one hand, the combination of minor laundering effects of WRV and solid state NMR spectra, together with the large decrease in molecular mass are positive indications for the possibility of recycling cotton into regenerated cellulosic fibres. On the other hand, results show that the specific surface area decreased, which implies that the reactivity of cotton cellulose may decrease during long-term use and laundering.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Chemical and ultrastructural changes in cotton cellulose induced by laundering and textile use

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Lima et al (2003) showed that xyloglucans could be used as wet-end additives to improve the mechanical properties of the paper sheet. Köhnke et al (2010) showed that the adsorption of birch glucuronoxylan reduced the degree of drying-induced fiber wall cross-linking, resulting in the higher tensile strength of the paper sheet.…”

Section: Introductionmentioning

confidence: 99%

Improvements in Pulp Properties by Alkali Pre-Extraction and Subsequent Kraft Pulping With Controlling H-Factor and Alkali Charge

Sim¹,

Youn²,

Cho³

et al. 2012

BioResources

View full text Add to dashboard Cite

The objective of this study was to determine the processing conditions for obtaining improved pulp properties from the kraft pulping process with an alkali pre-extraction stage. Before the kraft pulping, a pre-extraction of hemicelluloses from mixed hardwood chips was performed with two different alkali concentrations (3% and 12% as Na 2 O) at 150 °C for 90 minutes. The kraft pulping of the pre-extracted chips was then conducted in two ways: with either the H-factor alone controlled or with both the Hfactor and the alkali charge controlled. When the chips were preextracted with the 3% alkali charge and with the kraft pulping controlled to an H-factor of 500, the yield and properties of the pulp were higher than those of the reference kraft pulp. The 12% alkali pre-extraction and kraft pulping resulted in a low yield of screened pulp. However, when the alkali charge and the H-factor were adjusted together, the pulp yield remained constant and the pulp properties improved in comparison to the reference pulp for both the 3 and 12% cases.

show abstract

“…During the process of hornification, the fibers suffer changes that are directly related to their structure. In the outer cell wall occurs collapsing and hardening, which prevents the complete wetting of the fiber, which means reduction in the water absorption capacity and swelling of the fiber (68,69).…”

Section: Thermal Treatment Of the Vegetable Fibersmentioning

confidence: 99%

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

et al. 2015

View full text Add to dashboard Cite

The present review shows the state-of-art on the approachs about improving the processing, physical-mechanical performance and durability of non-conventional fiber-cement composites. The objective of this review is to show some of these strategies to mitigate the degradation of the vegetable fibers used as reinforcement in cost-effective and non-conventional fiber-cement and, consequently, to improve their mechanical and durability properties for applications in the housing construction. Beyond the introduction about vegetable fibers, the content of this review is divided in the following sections: (i) surface modification of the fibers; (ii) improving fiber-to-cement interface; (iii) natural pozzolans; (iv) accelerated carbonation; (v) applications of nanoscience; and (vi) principles of functionally graded materials and extrusion process were briefly discussed with focus on future research needs. RESUMEN: Compuestos cementantes no convencionales reforzados con fibras vegetales: Una revisión de estrategias para mejorar la durabilidad.La presente revisión explora la actualidad en el campo de los compuestos de fibrocemento no convencionales en relación a mejoras en el proceso productivo, el rendimiento físico-mecánico y la durabilidad. El objetivo de esta revisión es exponer algunas estrategias para mitigar la degradación de las fibras vegetales utilizadas como refuerzo en fibrocementos no convencionales y rentables, obteniendo en consecuencia una mejoría en el rendimiento de sus propiedades mecánicas y durabilidad para su aplicación en el área de la construcción de viviendas. Además de la introducción en relación a las fibras vegetales, el contenido de esta revisión se divide en las siguientes secciones: (i) modificación de la superficie de las fibras; (ii) mejoramiento de la interfaz fibra-cemento; (iii) puzolanas naturales; (iv) carbonatación acelerada; (v) aplicaciones de la nanociencia; y (vi) principios de los materiales funcionalmente graduados y el proceso de extrusión fueron discutidos brevemente con un enfoque a investigaciones futuras.

show abstract

Kraft pulp hornification: A closer look at the preventive effect gained by glucuronoxylan adsorption

Cited by 74 publications

References 23 publications

Chemical and ultrastructural changes in cotton cellulose induced by laundering and textile use

Chemical and ultrastructural changes in cotton cellulose induced by laundering and textile use

Improvements in Pulp Properties by Alkali Pre-Extraction and Subsequent Kraft Pulping With Controlling H-Factor and Alkali Charge

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

Contact Info

Product

Resources

About