Alkali Uptake and Swelling Behavior of Lyocell Fiber and their Effects on Crosslinking Reaction

Okubayashi, Satoko; Bechtold, Thomas

doi:10.1007/s10570-005-2204-1

Cited by 18 publications

(13 citation statements)

References 18 publications

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“…The general equations used for PEK’s model are given by where M t is the mass change at any time t , M 1 and M 2 are the masses at equilibrium, τ 1 and τ 1 are characteristic times for which M 1 and M 2 are reached, respectively, and M 1+2 corresponds to the sum of M 1 and M 2 . Subscripts 1 and 2 indicate a fast and a slow kinetic process, corresponding to the sorption sites …”

Section: Results and Discussionmentioning

confidence: 99%

Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation

et al. 2017

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The coefficient of hygroscopic swelling (CHS) of self-organized and shear-oriented cellulose nanocrystal (CNC) films was determined by capturing hygroscopic strains produced as result of isothermal water vapor intake in equilibrium. Contrast enhanced microscopy digital image correlation enabled the characterization of dimensional changes induced by the hygroscopic swelling of the films. The distinct microstructure and birefringence of CNC films served in exploring the in-plane hygroscopic swelling at relative humidity values ranging from 0% to 97%. Water vapor intake in CNC films was measured using dynamic vapor sorption (DVS) at constant temperature. The obtained experimental moisture sorption and kinetic profiles were analyzed by fitting with Guggenheim, Anderson, and deBoer (GAB) and Parallel Exponential Kinetics (PEK) models, respectively. Self-organized CNC films showed isotropic swelling, CHS ∼0.040 %strain/%C. By contrast, shear-oriented CNC films exhibited an anisotropic swelling, resulting in CHS ∼0.02 and ∼0.30 %strain/%C, parallel and perpendicular to CNC alignment, respectively. Finite element analysis (FEA) further predicted moisture diffusion as the predominant mechanism for swelling of CNC films.

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Section: Results and Discussionmentioning

confidence: 99%

Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation

et al. 2017

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“…Then the fibers were dried in room temperature followed by oven drying for 3 h at 105°C. Fiber behavior on alkali treatment was studied in previous research (Ramamoorthy et al 2014;Jaturapiree et al 2006;Okubayashi and Bechtold 2005).…”

Section: Alkali Treatmentmentioning

confidence: 99%

Performance of biocomposites from surface modified regenerated cellulose fibers and lactic acid thermoset bioresin

et al. 2015

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The effect of surface treatments, silane and alkali, on regenerated cellulose fibers was studied by using the treated fibers as reinforcement in lactic acid thermoset bioresin. The surface treatments were performed to improve the physico-chemical interactions at the fiber-matrix interface. Tensile, flexural and impact tests were used as indicator of the improvement of the interfacial strength. Furthermore, thermal conductivity, viscoelasticity measurements as well as microscopy images were made to characterize the fiber surface treatments and the effect on adhesion to the matrix. The results showed that silane treatment improved the mechanical properties of the composites as the silane molecule acts as link between the cellulose fiber and the resin (the fiber bonds with siloxane bridge while the resin bonds with organofunctional group of the bi-functional silane molecule) which gives molecular continuity in the interphase of the composite. Porosity volume decreased significantly on silane treatment due to improved interface and interlocking between fiber and matrix. Decrease in water absorption and increase in contact angle confirmed the change in the hydrophilicity of the composites. The storage modulus increased when the reinforcements were treated with silane whereas the damping intensity decreased for the same composites indicating a better adhesion between fiber and matrix on silane treatment. Thermogravimetric analysis indicated that the thermal stability of the reinforcement altered after treatments. The resin curing was followed using differential scanning calorimetry and the necessity for post-curing was recommended. Finite element analysis was used to predict the thermal behavior of the composites and a non-destructive resonance analysis was performed to ratify the modulus obtained from tensile testing. The changes were also seen on composites reinforced with alkali treated fiber. Microscopy images confirmed the good adhesion between the silane treated fibers and the resin at the interface.

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“…The wet sample was dried at 105 ºC for 2 h and the dry weight was recorded (W d ). The water retention value (WRV) was calculated from the following equation (9) :…”

Section: Water Retention Value (Wrv)mentioning

confidence: 99%

Physical Modification of Lyocell® and Modal® Fabrics and its Effect on Fabric Dyeability

2010

Egypt. J. Chem.

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HE EFFECT of some swelling agents; Viz. alkali metal hydroxides, alkaline earth metal salt and heavy metal salt, on the dyeability of lyocell and modal fabrics with reactive and direct dyes was monitored. The dyeing characteristics; namely colour strength, dyeing isotherm, diffusion coefficient, dyeing rate constant and half dyeing time of the dyed fabrics were assessed. The colour strength of the dyed samples increased in the order ZnCl 2 > MgCl 2 > NaOH > KOH > untreated. The fastness properties of the dyed fabrics were investigated. X-ray diffraction patterns of both untreated as well as treated fabrics were used to assign the change in the fine structure of the swollen lyocell and modal fibres relative to their respective untreated ones. The water retention capacity of lyocell and modal fabrics was calculated to deduce the degree of crystallinty of treated as well as untreated lyocell and modal fabrics.

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Alkali Uptake and Swelling Behavior of Lyocell Fiber and their Effects on Crosslinking Reaction

Cited by 18 publications

References 18 publications

Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation

Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation

Performance of biocomposites from surface modified regenerated cellulose fibers and lactic acid thermoset bioresin

Physical Modification of Lyocell® and Modal® Fabrics and its Effect on Fabric Dyeability

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