Reza Ghaffari Sani; Foroogh Dastoorian; seyed Majid Zabihzadeh; Mohammad Tasooji
Abstract
In recent years, plant oils usage as matrix in natural fiber reinforced polymer composites, has been considered because of increasing environmental concern. In the present research work, acrylated epoxidized soybean oil combined with maleic anhydride and styrene as a matrix and wheat straw flour as filler ...
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In recent years, plant oils usage as matrix in natural fiber reinforced polymer composites, has been considered because of increasing environmental concern. In the present research work, acrylated epoxidized soybean oil combined with maleic anhydride and styrene as a matrix and wheat straw flour as filler was used for making a relatively biodegradable composite. In order to find the optimum synthesis time of resin, during reaction of maleic anhydride with acrylated epoxidized soybean oil, three time level of 60, 90 and 120 min, polymer was prepared and cross link density was determined with “solvent swelling” method. The optimum synthesis time of resin was obtained 90 min. Afterwards, maleated acrylated epoxidised soybean oil was mixed with 25% of styrene and 60 mesh wheat straw flour in three weight ratio of 20, 30 and 40% manually. The combination of resin and wheat straw flour was poured in a steel mold and pressing was applied manually. The die was placed in an oven at temperature of 140oC for one hour. Infrared spectroscopy, Thermogravimetric analysis tensile and impact test was conducted to evaluate and analyze the physical and mechanical properties of the resulted composite. Infrared spectroscopy results showed ether bond formation between hydroxyl groups of wheat straw and carbonyl groups of resin. Water absorption test results showed no statistical difference between water absorption values of three loading of wheat straw till 144 hours of immersion, however at 168 hours of immersion, water absorption values were increased with increase of wheat straw loading. There was no statistical difference between thickness swelling values of composites with different wheat straw loading. With increasing wheat straw loading, tensile strength and modulus was increased significantly. Also the impact strength increased as an increase of wheat straw loading.
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.
Management and Economics wood
Lila Asadi khoramabadi; Abolghasem Khazaeian; Mohammad reza Masteri Farahani; Alireza Shakeri
Abstract
Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties ...
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Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties of wood. In this research, to improve the mechanical properties with other properties of wood, soybean oil modified with maleic anhydride was used for thermal treatment. Wood speciments were subjected to heat treatment soybean oil modified with maleic anhydride at two temperature (180 and 200° C ) and three time (2, 4 and 6 hours). Untreated beech was used as comparison for each treatment conditions. In this study, the effects of heat treatment on physical properties )water absorption and volumetric changes) and mechanical properties such as Bending strength) ISO 3133-1975(, Compression strength Parallel to grain) ISO 3787-1976 (and Impact bending) DIN 52189( were examined. The test results of heat-treated with modified soybean oil and control samples showed that physical and mechanical properties increases with heat treatment.
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard; Fardad Golbabaei
Abstract
The goal of this study was to investigate the use of bagasse fibers as raw material for making laboratory medium density fiberboard (MDF). Effect of treatment (with maleic anhydride and without maleic anhydride) of fibers and the press temperatures (180 ºC , 190 ºC , and 200 ºC) ...
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The goal of this study was to investigate the use of bagasse fibers as raw material for making laboratory medium density fiberboard (MDF). Effect of treatment (with maleic anhydride and without maleic anhydride) of fibers and the press temperatures (180 ºC , 190 ºC , and 200 ºC) on the mechanical and dimensional stability properties of MDF panels were determined. Physical (thickness swelling, water absorption, and swilling in water at ambient temperatures and in steam for 12-216 h.) and mechanical properties (modulus of rupture, modulus of elasticity, and internal bond strength) of the panels were determined according to the procedure of EN standards.This study showed all MDF panels made from bagasse fibers treated with maleic anhydride (MA) at 190 ºC press temperature had the highest values among the other types of specimens for general purpose boards. The thickness swelling and water absorption value with treated bagasse fibers and 190 ºC press temperature were very lower than all MDF panels. Treated bagasse fibers at 190 ºC show a minimum steam absorption. The absorption of steam increase with increase in time from 2 to 120 h in all the six treatments. Beyond 120 h. no additional absorption of steam is found in any of the six MDF boards.
