Management and Economics wood
Elham Hatamzadeh Arabi; Maryam Ghorbani; Prya Biparva
Abstract
The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc ...
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The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc oxide nanoparticles, nanocomposite and nano/Styrene. Mechanical and biological tests samples according toASTM-D143 and EN113 respectively were treated by vacuum- pressure method using cylinder experimental. The mechanical tests were considered for each level 5 repeat and for biological test for each level 10 repeat. The presence of zinc oxide nanoparticles on cell wall and styrene in the cell cavities were confirmed by Scanning electron microscopy. According to the results, bending strength, bending modulus, hardness and pressure parallel to grain for nano/styrene samples with highest improvement were increased 36.74, 40.23, 60.58 and 25.07 in comparison with control respectively. Also, decay resistance of treated samples increased, so that maximum and least weight loss were recorded for control and nano/styrene samples with 25.81 and 3.37% weight loss.
Management and Economics wood
Neda Esmaeili; Maryam Ghorbani; Porya Biparva
Abstract
In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently ...
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In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently with paraffin by vacuum-pressure method. Increasing concentration of glutaraldehyde caused to weight gain and bulking wood cell wall, subsequently reduced paraffin penetration into the porous structure of wood. Biological resistance exposed to white rot fungi and mechanical properties were measured according to the standards EN113 and ASTM D143-94, respectively. Scanning electron microscopic images showed bulking of cell walls and paraffin presence in cell cavities. According to results of TGA, increasing of modification intensity decreased mass loss due to cross linking formation between glutaraldehyde and cell wall polymers. Paraffin at combined modification containing 10% and 20% glutaraldehyde improved significantly the modulus of elasticity. Glutaraldehyde reduced bending strength, but paraffin present in the modified samples improved it. The Glutaraldehyde increased compression strength parallel to grain and hardness that the improvement was more obvious in combined modification. Modification with glutaraldehyde enhanced decay resistance exposed to white rot fungi, and this improvement intensified at the presence of paraffin. Inhibitory influence of chemical modification on wood attacking white rot fungi can be attributed to decreases the wood moisture, bulking of cell walls and blocking cell cavities.
Management and Economics wood
Elham Hatamzadeh; Maryam Ghorbani; Poria bi parva
Abstract
In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according ...
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In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according to ASTM-D4446-05, and divided to three levels; control, Zncl2/NH3 and Zncl2/Naoh at 0.05M concentration and pH=10. Test samples were impregnated with salty precursor in the experimental cylinder using vacuum-pressure method, and in order to adjust the pH, soda and ammonia added. Due to the electron microscope images, change the type of precursor deposition, caused the different structure of ZnO nanoparticle. Retention of zinc oxide nanoparticles, density changes, water absorption, swelling and anti-swelling efficiency (ASE) were determined after synthesis. Retention of zinc chloride precursor with ammonia and soda acidity regulator was determined 4.43 and 1.71kg/m3 respectively. Water absorption increased at first hours of immersion, and then decreased. These treatments increased water absorption of wood. Least swelling and water absorption, and maximum ASE were measured in Zncl2/NH3 level.
