Influence of fungal infection on the long-term water absorption and morphological behavior of bagasse fiber/polypropylene composites at different exposure times

2013 ◽  
Vol 20 (4) ◽  
pp. 351-357 ◽  
Author(s):  
Behzad Kord ◽  
Seyyed Khalil Hosseinihashemi ◽  
Mehdi Modirzare
Keyword(s):  
Water Absorption ◽  
Diffusion Coefficients ◽  
Water Diffusion ◽  
White Rot ◽  
Fungal Decay ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
Bagasse Fiber ◽  
Control Samples

AbstractIn this study, the effect of fungal decay on the long-term water absorption of bagasse fiber/polypropylene composites at different exposure times was studied. For this purpose, the blend composites were prepared through the melt mixing of bagasse fiber with polypropylene at 40:60% weight ratios, with 2% coupling agent for all formulations. Then, the samples were exposed to brown-rot (Coniophora puteana) and white-rot (Trametes versicolor) fungal treatments for 8, 12 and 16 weeks with the Kolle flask method. The long-term water absorptions of samples were evaluated by immersing them in water at room temperature for several weeks, and water diffusion coefficients were also calculated by evaluating the water absorption isotherms. Also, the morphology of composites was characterized using scanning electron microscopy (SEM). The results showed that the water absorption of samples was actually much higher after both types of rotting and was significantly higher than that of control samples. Also, the water absorption of white-rotted samples was higher than that of brown-rotted and control samples for all weeks of fungal exposure times. In addition, the control sample and composite after 16 weeks of exposure to white-rot fungi exhibited the lowest and highest water diffusion coefficients, respectively. The mechanism of water absorption of samples against fungal decay at different exposure times followed the kinetics of a Fickian diffusion process. Furthermore, the SEM micrographs showed that the extent of degradation increased with increasing exposure time to fungus.

Water Absorption Characteristics of Obatanpa and Mamaba Maize Hybrids (Zea mays)

2006 ◽  
Vol 2 (3) ◽  
Author(s):  
Ahmad Addo ◽  
Ato Bart-Plange ◽  
Komla Dzisi
Keyword(s):  
Zea Mays ◽  
Diffusion Coefficient ◽  
Water Absorption ◽  
Diffusion Coefficients ◽  
Type Equation ◽  
Water Diffusion ◽  
Energy Of Activation ◽  
Absorption Kinetics ◽  
Maize Hybrids ◽  
Absorption Characteristics

Water absorption characteristics of two newly-released maize hybrids, Obatanpa and Mamaba, during soaking were measured at four temperatures of 30, 40, 50 and 60ºC. The absorption kinetics followed the Fick's law of diffusion during the first hours of soaking. The values determined for water diffusion coefficients varied from 7.31 x 10-12 to 9.33 x 10-12 m2/s and from 6.30 x 10-12 to 8.25 x 10-12 m2/s for Obatanpa and Mamaba respectively. An Arrhenius–type equation was used to relate the diffusion coefficient of Obatanpa and Mamaba to temperature, and the energy of activation for Obatanpa and Mamaba was estimated. The values determined were 6.54 kJ/mol and 6.82 kJ/mol for Obatanpa and Mamaba respectively.

Empirical Dissolution Rate Law for the Glass R7T7 Contacting Halite- and Silica-Saturated Brines

1991 ◽  
Vol 257 ◽  
Author(s):  
B. Grambow ◽  
W. Lutze ◽  
R. Müller
Keyword(s):  
Time Dependence ◽  
Dissolution Rate ◽  
Diffusion Coefficients ◽  
Water Diffusion ◽  
Square Root ◽  
Borosilicate Glasses ◽  
Rate Law ◽  
Apparent Diffusion Coefficients ◽  
Apparent Diffusion

ABSTRACTWe report on the time dependence of release of glass constituents during static dissolution experiments with the COGEMA glass R7T7 in saline MgCl2 and NaCl dominated solutions at temperatures between 110 and 190°C. The experiments were performed at high S/V values to ensure silica saturation almost from the start of the tests. The results show a square root of time dependence indicating diffusion as rate-controlling with apparent diffusion coefficients similar to that of water diffusion in alkali silicate, borosilicate glasses or long-term weathered obsidians.

scholarly journals Decay resistance, hardness, water absorption, and thickness swelling of a bagasse fiber/plastic composite

BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 3289-3299 ◽  
Author(s):  
Seyyed Khalil Hosseinihashemi ◽  
Mahdi Modirzare ◽  
Vahidreza Safdari ◽  
Behzad Kord
Keyword(s):  
Water Absorption ◽  
Exposure Time ◽  
Decay Resistance ◽  
White Rot ◽  
Distilled Water ◽  
Thickness Swelling ◽  
Fungal Exposure ◽  
Plastic Composite ◽  
Bagasse Fiber ◽  
Composite Samples

The decay resistance, hardness, water absorption, and thickness swelling of a bagasse fiber/polypropylene composite were evaluated. Brown- (Coniophora puteana) and white-rot (Trametes versicolor) fungal treatments were applied for 8, 12, and 16 weeks according to BS 838:1961 with the kolle-flask method. The brown- and white-rotted, and control composite samples were immersed in distilled water at 2 h and 24 h to measure the water absorption and thickness swelling of samples according to the ASTM D 570-98 requirements. Results indicated that the both lowest (3.2%) and the highest (7.2%) weight loss were observed in the white-rotted composite samples for 8 and 16 weeks fungal exposure times, respectively. The highest hardness (77.6 Shore D) was noted in the control composite samples, and the lowest hardness (65.5 Shore D) was recorded in the white-rotted composite samples. The highest water absorption (10.5%) was observed in the brown-rotted composite samples for 8 weeks fungal exposure time and after 24 h immersion in distilled water, and the lowest (3.8%) was noted in the control composite samples after 2 h immersion in distilled water. The highest thickness swelling (6.3%) was observed in the control composite samples after 24 h immersion in distilled water, and the lowest thickness swelling (1.9%) was found in the white-rotted composite samples for 16 weeks fungal exposure time and after 2 h immersion in distilled water.

Effect of immidazolium-based green solvents on the moisture absorption and thickness swelling behavior of wood flour/polyethylene composites

2020 ◽  
pp. 089270572096217
Author(s):  
Behzad Kord ◽  
Mohammad Dahmardeh Ghalehno ◽  
Farnaz Movahedi
Keyword(s):  
Diffusion Coefficients ◽  
Moisture Absorption ◽  
Wood Flour ◽  
Untreated Wood ◽  
Water Diffusion ◽  
Swelling Behavior ◽  
Interfacial Region ◽  
Thickness Swelling ◽  
Melt Mixing ◽  
Swelling Rate

The water transport kinetics and moisture-induced thickness swelling behavior of wood-plastic composites (WPCs) in the presence of two imidazolium-based ionic liquids (ILs) were studied. The wood flour chemically treated with ILs were compounded through melt mixing of high-density polyethylene and coupling agent, and finally, the test specimens were produced by compression molding. Hygroscopic rates of the composites were evaluated by immersing them in the water at room temperature and monitoring moisture sorption and thickness changes for several weeks. Besides, the water diffusion coefficients and swelling rate parameters were measured for all composites. It was found that the water absorption and thickness swelling of the WPC specimens reduced as a result of ILs treatment. The SEM analysis revealed that the presence of ILs can improve the quality of adhesion between the polymer matrix and the cellulosic materials, to decrease the gaps in the interfacial region and block the hydrophilic groups. Studying the water sorption process in the specimens showed that the process follows kinetics and mechanisms described by Fick’s law. The highest water diffusion coefficients and swelling rate parameters were found in composites with untreated wood.

scholarly journals Modelling of the Water Absorption Kinetics and Determination of the Water Diffusion Coefficient in the Pith ofRaffia viniferaof Bandjoun, Cameroon

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
E. Tiaya Mbou ◽  
E. Njeugna ◽  
A. Kemajou ◽  
N. R. Tagne Sikame ◽  
D. Ndapeu
Keyword(s):  
Water Absorption ◽  
Diffusion Coefficients ◽  
Gravimetric Method ◽  
Water Diffusion ◽  
Radial Position ◽  
Absorption Kinetics ◽  
Absorption Phenomenon ◽  
Longitudinal Position ◽  
Percentage Of Water Absorption ◽  
Two Stages

The present work focuses on the study of the water absorption phenomenon through the pith ofRaffia viniferaalong the stem. The water absorption kinetics was studied experimentally by the gravimetric method with the discontinuous control of the sampling mass at temperature of 30°C. The samples of 70 mm × 8 mm × 4 mm were taken from twelve sampling zones of the stem ofRaffia vinifera. The result shows that the percentage of water absorption of the pith ofRaffia viniferaincreases from the periphery to the center in the radial position and from the base to the leaves in the longitudinal position. Fick’s second law was adopted for the study of the water diffusion. Eleven models were tested for the modelling of the water absorption kinetics and the model of Sikame Tagne (2014) is the optimal model. The diffusion coefficients of two stages were determined by the solution of the Fick equation in the twelve sampling zones described by Sikame Tagne et al. (2014). The diffusion coefficients decreased from the center to the periphery in the radial position and from the base to the leaves in the longitudinal position.

scholarly journals Resistance of Injection Molded Wood-Polypropylene Composites against Basidiomycetes According to EN 15534-1: New Insights on the Test Procedure, Structural Alterations, and Impact of Wood Source

Fibers ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 92
Author(s):  
Kim Christian Krause ◽  
Christian Brischke ◽  
Tim Koddenberg ◽  
Andreas Buschalsky ◽  
Holger Militz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Test Procedure ◽  
Wood Particle ◽  
White Rot ◽  
Modulus Of Rupture ◽  
Fungal Decay ◽  
Decay Fungi ◽  
Polypropylene Composites ◽  
Injection Molded ◽  
Molded Wood

In this study, we investigated injection molded wood-polypropylene composites based on various wood sources and their decay resistance against white rot (Trametes versicolor) and brown rot (Coniophora puteana) in a laboratory test according to EN 15534-1:2014. The manufactured composites consisted of poplar (Populus spp.), willow (Salix spp.), European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) H. Karst.), and a commercial wood source (Arbocel® C100), respectively. All formulations were compounded on a co-rotating twin screw extruder and subsequently injection molded to wood–PP specimens with a wood content of 60% or 70% by weight. It was found that the test procedure had a significant effect on the mechanical properties. Loss in mechanical properties was primarily caused by moisture and less by fungal decay. Moisture caused a loss in the modulus of rupture and modulus of elasticity of 34 to 45% and 29 to 73%, respectively. Mean mass and wood mass losses were up to a maximum of 3.7% and 5.3%, respectively. The high resistance against fungal decay was generally attributed to the encapsulation of wood by the polymer matrix caused by sample preparation, and enhanced by reduced moisture uptake during the preconditioning procedure. Notable differences with respect to the wood particle source and decay fungi were also observed. Structural characterization confirmed the decay pattern of the fungi such as void cavities close the surface and the deposition of calcium oxalates.

Assessment of Impact Energy, Wear Behavior, Thermal Resistance and Water Absorption Properties of Hybrid Bagasse Fiber/CaCO3 Reinforced Polypropylene Composites

2021 ◽  
Vol 36 (2) ◽  
pp. 205-212
Author(s):  
I. O. Oladele ◽  
A. D. Akinwekomi ◽  
I. O. Ibrahim ◽  
M. H. Adegun ◽  
S. I. Talabi
Keyword(s):  
Calcium Carbonate ◽  
Thermal Resistance ◽  
Water Absorption ◽  
Impact Energy ◽  
Wear Behavior ◽  
Wear Test ◽  
Absorption Properties ◽  
Polypropylene Composites ◽  
The Impact ◽  
Bagasse Fiber

Abstract To harness the inherent advantages of both synthetic and natural reinforcements, mercerized bagasse fibers (BF) and particulate calcium carbonate (CaCO3) were utilized as a complementing reinforcement for the fabrication of bagasse fiber/calcium carbonate (BF/CaCO3) polypropylene composites. Two sets of composites were produced – one with mercerized BF/CaCO3 and the other with unmercerized BF/ CaCO3. The effect of reinforcement loading on the impact energy, wear behavior, thermal resistance and water absorption properties of the composites were studied. Results showed that the mercerized BF/CaCO3 hybrid reinforced polypropylene composites exhibited significant increase in impact energy and offered better resistance to weight loss during wear test. Similarly, the thermal resistance of the mercerized composites was higher than their corresponding unmercerized composites. Additionally, water absorption in mercerized composites was highly resisted than in unmercerized samples. These results indicated that mercerization treatment and reinforcement hybridization improved the impact energy, wear, thermal resistance and water ingress resistance of hybrid fiber/ particulate reinforced polypropylene composites.

Towards an Intrinsic Relationship between Diffusion Coefficients and Microscopic Features of Cements ?

2000 ◽  
Vol 663 ◽  
Author(s):  
P. Lovera ◽  
C. Galle ◽  
P. Le Bescop
Keyword(s):  
Diffusion Coefficients ◽  
Chemical Compounds ◽  
Water Diffusion ◽  
Mass Ratio ◽  
Microscopic Features ◽  
Long Term Behavior ◽  
Simple Modeling

ABSTRACTLong-term behavior of cemented waste packages requires the knowledge of water diffusion coefficients (water is supposed to be the main degradation agent, by solubilization of some chemical compounds). A simple modeling, based on the use of hydration code CEMHYD3D is proposed and validated for pure OPC pastes (sound or degraded) at mass ratio water / cement lying between 0.25 and 0.65. The nature of the porosity available for diffusion and the role of residual anhydrous compounds are discussed.

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