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
Azadeh Nikkhah Shahmirzadi; Maryam Ghorbani; Seyed Mojtaba Amininsab
Abstract
This research was conducted to investigate the effect of modification with maleic anhydride and methyl methacrylate on mechanical properties and decay resistance of poplar wood. Samples of mechanical and biological resistance tests were prepared according to ASTM D143-94 and EN113 standards. Treatment ...
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This research was conducted to investigate the effect of modification with maleic anhydride and methyl methacrylate on mechanical properties and decay resistance of poplar wood. Samples of mechanical and biological resistance tests were prepared according to ASTM D143-94 and EN113 standards. Treatment levels were divided into 4 groups; control, methyl methacrylate, maleic anhydride and combined of maleic anhydride/ methyl methacrylate. Samples were impregnated with maleic anhydride and monomer using vacuum- pressure method with experimental cylinder. Maleic anhydride treated samples were heated in oven for 4 and 24 hours at 150 and 103ºC. For polymerization, methyl methacrylate monomer treated samples were heated in oven at 90ºC for 24 hours, consequently at 103ºC for the same time. Methyl methacrylate polymer coating formed on the cell wall, causing 22.57% improvement in the lateral stability under pressure parallel to grain. Highest value in modules of rupture, elasticity and hardness were measured in combined level with 24.13, 47.13 and 45.53% improvement compared with the control, respectively. Maleic anhydride in the presence of methyl methacrylate, with decreasing polarity of the wood and create a good distribution of the particle and the polymer, resulting in the cross linking formation and transmission of uniform tension that would lead to improved mechanical properties. Also, decay resistance was improved in all levels of modification, so that weight loss declined from 80.4% in control to 4.29% in combined level. Modified with maleic anhydride because of the wood composition change, reduction in moisture absorption ability of cell wall and bulking effect, and the presence of methyl methacrylate in the cell cavities as a physical barrier to the movement of fungi mycelium and moisture, were leading to improved decay resistance.
Composite wood products
Amineh Behzadi Shahrebabak; Mehrab Madhoushi; Mohammad reza MastriFarahani
Abstract
In this study, the effect of nanoclay and coupling agent on decay resistance and physical properties (including water absorption and thickness swelling) of nanoclay- Polyethylene- MDF sanding- powder composite were investigated. For this aim, MDF sanding dust and polyethylene were used as lignocellulose ...
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In this study, the effect of nanoclay and coupling agent on decay resistance and physical properties (including water absorption and thickness swelling) of nanoclay- Polyethylene- MDF sanding- powder composite were investigated. For this aim, MDF sanding dust and polyethylene were used as lignocellulose and thermoplastic material respectively. Also, Maleic anhydride grafted polyethylene (MAPE) was used in different weight percentages; 3% and 6% as a compatibilizer and nanoclay .Cloisite®15A was used in different weight percentages 2%, 4% and 6%.At first, raw materials were producted to fabricate granules by using twin-screw extruder. Then 36 panels (12 treatments by 3 repetitions) were made by hot pressing with 1 g/cm3 nominal density at dimensions by 30 cm × 28 cm × 1 cm. Then, water absorption and thickness swelling and decay resistant (loss weight) were investigated. Specimens were exposed to Trametes versicolor for 3 months, according to ASTM-D1413 standard. The results shown, water absorption and thickness swelling reduce with increasing MAPE significantly. While, at the time when nanoclay was added 2% (phr), water absorption and thickness swelling reduced significantly and then increased. Also, decay resistance was improved with increasing coupling agent and nanoclay.
