Analysis of fibre deformation processes in high-consistency refining based on Raman microscopy and X-ray diffraction
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Wadood Y. Hamad
,
Norayr Gurnagul
Abstract
Raman microscopy has been used for the first time to predict the degree of micro-compressions in pulp fibres by monitoring the shift of the 1095 cm-1 Raman sensitive band under external loading. Strain sensitivity – the rate of change of Raman shift with respect to applied strain – provided a quantifiable measure of the degree of micro-compressions in pulp fibres. A methodology was developed to relate structure-property-process relations in high consistency refining (HCR) under atmospheric and pressurised conditions (AHRC and PHCR, respectively) based on powder X-ray diffraction and Raman microscopy. The state of stress and interfibrillar deformation of the cellulosic microfibrils within the cell wall were examined rigorously. PHCR pulps have a propensity for larger crystallite size, as well as larger portions of crystalline and paracrystalline components, thereby resulting in a more stressed microfibrillar arrangement mesoscopically. The higher density of cellulose chain packing and stressing renders the microfibrils more resistant to applied strain (yielding lower strain sensitivity through the Raman measurement). At the macroscopic level, the changes in the nano- and microscale are translated into a higher degree of micro-compression, or larger concertina-like, large-scale deformations; this can be observed as a more elastic-plastic macroscopic behaviour. Examination of the resistance of fibre curl and/or kinks in PHCR pulps against applied stress, supported the hypothesis that PHCR induces more micro-compressions. This macroscopic change in PHCR pulp fibres is also manifest in better properties of hand-sheets, such as stretch and tensile energy absorption.
©2012 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Masthead
- Masthead
- Original Papers
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 1. Syntheses and characterizations
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 2. Action in soda pulping conditions on softwood and phenolic β-O-4 lignin models
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 3. Delignification of softwood and action on a phenolic β-O-4 lignin model in kraft pulping conditions
- Analysis of fibre deformation processes in high-consistency refining based on Raman microscopy and X-ray diffraction
- Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy
- Chemical improvement of surfaces. Part 2: Permanent hydrophobization of wood by covalently bonded fluoroorganyl substituents
- Testing of the superhydrophobicity of a zinc oxide nanorod array coating on wood surface prepared by hydrothermal treatment
- Properties of molding plates made with albizia wood particles impregnated with alcohol-soluble PF resins prepared from phenol-liquefied lignins
- Within-ring movement of free water in dehydrating Norway spruce sapwood visualized by neutron radiography
- Influence of hygromechanical history on the longitudinal mechanosorptive creep of wood
- Effects of systematic variation of wood adherend bending stiffness on fracture properties: Part 1. Influence of grain angle
- Effects of systematic variation of wood adherend bending stiffness on fracture properties. Part 2. Revisiting traditional DCB analysis methods
- Determination of adhesive energy at the wood cell-wall/UF interface by nanoindentation (NI)
- Short Notes
- Distribution of extracts including 4,8-dihydroxy-5-methoxy-2-naphthaldehyde in Diospyros kaki analyzed by gas chromatography-mass spectrometry and time-of-flight secondary ion mass spectrometry
- Southern pine impregnated with silicate solution containing cellulose nanofibrils
- Meetings
- Meetings
Articles in the same Issue
- Masthead
- Masthead
- Original Papers
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 1. Syntheses and characterizations
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 2. Action in soda pulping conditions on softwood and phenolic β-O-4 lignin models
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 3. Delignification of softwood and action on a phenolic β-O-4 lignin model in kraft pulping conditions
- Analysis of fibre deformation processes in high-consistency refining based on Raman microscopy and X-ray diffraction
- Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy
- Chemical improvement of surfaces. Part 2: Permanent hydrophobization of wood by covalently bonded fluoroorganyl substituents
- Testing of the superhydrophobicity of a zinc oxide nanorod array coating on wood surface prepared by hydrothermal treatment
- Properties of molding plates made with albizia wood particles impregnated with alcohol-soluble PF resins prepared from phenol-liquefied lignins
- Within-ring movement of free water in dehydrating Norway spruce sapwood visualized by neutron radiography
- Influence of hygromechanical history on the longitudinal mechanosorptive creep of wood
- Effects of systematic variation of wood adherend bending stiffness on fracture properties: Part 1. Influence of grain angle
- Effects of systematic variation of wood adherend bending stiffness on fracture properties. Part 2. Revisiting traditional DCB analysis methods
- Determination of adhesive energy at the wood cell-wall/UF interface by nanoindentation (NI)
- Short Notes
- Distribution of extracts including 4,8-dihydroxy-5-methoxy-2-naphthaldehyde in Diospyros kaki analyzed by gas chromatography-mass spectrometry and time-of-flight secondary ion mass spectrometry
- Southern pine impregnated with silicate solution containing cellulose nanofibrils
- Meetings
- Meetings
