Research Paper
PANTEA OMRANI; Hamideh Abdolzadeh; Mohsen Abedi
Abstract
Fiber Reinforced Polymer (FRP) has become one of the most popular methods in the reinforced, repair and rehabilitation of structure due to its ease of application and the special physical characteristics. Both destructive and nondestructive assessments have been used to test the characteristics and durability ...
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Fiber Reinforced Polymer (FRP) has become one of the most popular methods in the reinforced, repair and rehabilitation of structure due to its ease of application and the special physical characteristics. Both destructive and nondestructive assessments have been used to test the characteristics and durability of FRP in order to investigate the condition of the structure. The aim of this research was to investigate the structural performance of corner joint reinforced with fiber reinforced polymer (FRP) composite under diagonal tension load. Constructed joints from two wooden species of beech (Fagus orientalis) and fir (Abies alba), were reinforced with reinforced composites of one and two layer of carbon and glass fibers and then they were tested under diagonal tension load. The miter corner joints were made with wooden pin and polyvinyl acetate adhesive. The fibers lay-up was done manually. Epoxy resin was used as a polymeric matrix. Result of investigation indicated that use of beech wood in comparison with fir exhibited better results. In addition, glass fibers have shown better performance than carbon fiber as reinforcing agents. Inspection of diagonal tension specimens after failure have indicated that using of FRPs on the surfaces of L-shaped miter prevent joint opening, however, failure was occurred at the joint by increasing of load and vertical displacement and the general wood weakness in tension perpendicular to the grain and shear parallel to the grain at dowels site due to stress concentration. Also the results showed that the miter corner joint made with beech species and two layers of glass fibers had the highest stress carrying capacity.
Research Paper
khadijeh armand; ali ghasemiyan
Abstract
This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan ...
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This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan and nanocytosis with concentration of 1 wt% , were prepared by dissolving in chloroform and 1% acetic acid, respectively. In both method done coating with three layers. Then, coated samples dried in oven. In the mixing method, polylactic acid and chitosan were mixed then coated on base paper. In the grafting method, by chemical modification of chitosan and polylactic acid, 0.01 g of EDC( N-(3-dimethy laminopropyl)-N/-ethylcarbodiimide hydrochloride) , 0.1 g of Span 80 and 0.047 g of HOBT( 1- Hydoxybenzotriazole) homogeneous solution were prepared and placed on a paper surface. Finally, investigated barrier and mechanical properties including contact angle, water absorption, air permeability and burst strength respectively. The results showed that papers which were coated with grafting method, with three layers of coating (P3nCs3) had the most strength air permeability compared to the mixing method, control sample showed minimum strength to air permeability. Water absorption decreased in coated samples by mixing method compared to grafting method that showed grafting method further reduced water absorption. Contact angle increased in coated samples by the grafting method compared to the mixing method.
Research Paper
shaghayegh rezanezhad; Hossein Resalati; Seyed Majid Zabihzadeh
Abstract
Biodegradable magnetic nanocomposites of cellulose have been widely used in adsorption of heavy metals from water. In this research, nano magnetic papers were produced by commercial craft long fiber (NMP), magnetic fibers with 1% gluconic acid (NMP / GA 1%), nanocrystalline cellulose (MNCC) as well as ...
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Biodegradable magnetic nanocomposites of cellulose have been widely used in adsorption of heavy metals from water. In this research, nano magnetic papers were produced by commercial craft long fiber (NMP), magnetic fibers with 1% gluconic acid (NMP / GA 1%), nanocrystalline cellulose (MNCC) as well as carboxymethyl cellulose (MCMC), and the adsorbents were used to remove heavy metals of lead (Pb) and nickel (Ni). The nanocomposites were evaluated by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and sample vibration magnetometer (VSM). X-ray diffraction patterns showed that magnetic fibers and composites were successfully produced and the nano magnetite peaks were observed in all samples. Examination of nano magnetite and cellulose nanocrystals showed that most of the particles were in the range of 1 - 19 and 1 - 65 nm, respectively. The highest magnetic saturation was related to the nanocrystalline cellulose magnetic composite. Adsorption samples were examined by a microwave plasma atomic emission spectrometer. The results of lead and nickel adsorption test showed that the NMP / GA 1%, MCMC and control sample adsorbents had highest and lowest amount of lead and nickel adsorption, respectively. Lead metal also has a higher adsorption than nickel with all the adsorbents.
Research Paper
Reza Jazayeri; saeed kazemi najafi; Habibollah Younesi; Abolfazl Kargarfard
Abstract
In this study, the effect of graphite and two modified graphite materials in reducing formaldehyde emission of medium density fiberboard (MDF) was investigated. For this purpose, expanded graphite (EG) was syntesyzed from graphite (G) and modified expanded graphite (MnO2-EG) was produced through the ...
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In this study, the effect of graphite and two modified graphite materials in reducing formaldehyde emission of medium density fiberboard (MDF) was investigated. For this purpose, expanded graphite (EG) was syntesyzed from graphite (G) and modified expanded graphite (MnO2-EG) was produced through the intercalation process of expanded graphite with manganese dioxide. Thus, three graphite materials were prepared for resin treatment. Molecular tests including X-ray diffraction (XRD) and X-ray diffraction spectroscopy (SEM-EDS) were performed to determine their molecular properties,. In addition, the differential scanning caliber test (DSC) test was performed to evaluate the thermal behavior of the resin under the influence of these graphite materials as additive. The additives were added to urea formaldehyde resin at three levels of consumption of 1, 2 and 3%, and then medium density fiberboard (MDF) with a density of 750 kg/m3 was made from glued fibers. After making the board, the formaldehyde emission test was performed by desiccator method. Overall, MnO2-EG showed better results than control and two other graphite treatments. The best performance was resulted by MnO2-EG at level 3% so that reduced formaldehyde emission by about 61%. It seams the formaldehyde molecules absorbed into the expanded graphite layers were exposed to oxidation by manganese dioxide molecules. On the other hand, as the DSC test showed, the highest anthalopy reaction occurred in resin treated by MnO2-EG, indicating an increase in the reaction of formaldehyde molecules in the resin structure.
Research Paper
mohammad ghofrani; Anooshe Fazeli
Abstract
This study was carried out to investigate the effect of two nominal density levels of 800 kg/m3 and 1100 kg/m3 and two levels of industrial wood to cement ratios of 25:75 and 35:65 on mechanical and physical properties of wood cement composites. Boards were produced and then observed density of boards ...
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This study was carried out to investigate the effect of two nominal density levels of 800 kg/m3 and 1100 kg/m3 and two levels of industrial wood to cement ratios of 25:75 and 35:65 on mechanical and physical properties of wood cement composites. Boards were produced and then observed density of boards were calculated. The experimental boards were subjected to modulus of elasticity and modulus of rupture tests in accordance with EN 310. Internal bonding was evaluated according to EN 319. Water absorption and thickness swelling were evaluated after 2 and 24 hours immersion in water according to EN 317. Fire resistance was evaluated according to ISO 11925. Results indicated that bending properties of the boards, including modulus of elasticity and modulus of rupture, and internal bonding all increased with increase in density. That was attributed to the high compression and improved connection between fiber and cement matrix. Modulus of elasticity increased significantly as cement content was raised. Modulus of rupture values were inversely related to cement content. Increasing wood to cement ratio led to low internal bonding because the low amount of cement can be insufficient to cover the wood particles for effective bonding to resist the tensile forces applied during internal bonding test. As the board density increased, dimensional stability increased. Variations in the wood to cement ratio have been reported to significantly affect the dimensional stability of specimens. Water absorption and thickness swelling increased with the increase in wood to cement ratio. Fire resistance of specimens improved when the board density and cement content increased. All of the mechanical properties of boards produced in this study satisfied the EN 634-2 requirements.
Research Paper
Masoumeh Mollaei; Mazaher Moeinaddini; Nematollah Khorasani; Mohammad Azadfallah; Amirhooman Hemmasi
Abstract
Sulfide ions (S-2 ) derived from Na2S remaining in black liqueur are the source of H2S gas production along the black liquor recovery cycle in the Kraft pulp and paper industry. In this study, we tried to prevent the production of H2S by removing the mentioned ions from black liquor by using of synthesized ...
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Sulfide ions (S-2 ) derived from Na2S remaining in black liqueur are the source of H2S gas production along the black liquor recovery cycle in the Kraft pulp and paper industry. In this study, we tried to prevent the production of H2S by removing the mentioned ions from black liquor by using of synthesized adsorbents (Cu-PAC and Cu-BWP100). The adsorbents were produced by immersing powdered activated carbon (PAC) and beech powder with 100 mesh (BWP100) in 0.1 M solution of CuCl2. The adsorbent properties were obtained before and after copper ion loading by FTIR, BET and SEM-FEI analyses. Finally, the performance of these adsorbents in the removal of S-2 from black liquor with three levels of sulfide (22%, 20, 18) was investigated. The results of FTIR, BET and SEM-FEI analysis showed that Cu+ 2 was located on the surfaces of raw organic material without any change in the structure of them. Experimental data for the Cu-PAC adsorbent showed that it was more agreement with the Freundlich equation and more follow to the pseudo-second-order kinetic model, whereas for Cu-BWP100 adsorbent it was the more consistent with the Langmuir equation and adherence to the pseudo-first-order kinetic model. The Cu-PAC adsorbent has the ability to remove 79.93% and Cu-BWP100 60.03% of S-2 from black liquor. The Cu-PAC, with its higher specific surface area, has a higher ability to remove S-2 from the black liquor than the Cu-BWP100. In general, the mentioned adsorbents will have a high ability to reduce H2S production by eliminating S-2.
Research Paper
Amir Nourbakhsh; Abolfazl Kargarfard; Reza Hajihassani; Saman Ghahri; Fardad Golbabaei
Abstract
In this study, the resistance properties of nanocomposite plastic wood produced using 5 levels of cellulosic wastes (bagasse, corn stalk, rice stalk, sunflower stem and canola stem), three levels of nanomaterials (carbon nanotubes, nano silica, nanoclay) ) And urban polymer wastes (PP polypropylene and ...
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In this study, the resistance properties of nanocomposite plastic wood produced using 5 levels of cellulosic wastes (bagasse, corn stalk, rice stalk, sunflower stem and canola stem), three levels of nanomaterials (carbon nanotubes, nano silica, nanoclay) ) And urban polymer wastes (PP polypropylene and HDPE heavy polyethylene, etc.) were investigated. In order to chemically bind the wood / polymer fiber composites, chemicals and reinforcers (pairing agents) have been used due to the hydrophilic properties of cellulose fibers and plastic drainage. Extruders and hot presses were used to study the mechanical properties and bonding of composites. The results showed that the use of HDPE heavy polymer wastes increased tensile strength, flexural modulus and impact resistance to polypropylene wastes. Regarding the use of agricultural wastes and wastes in the construction of wood-plastic composites, in general, the results have shown that the addition of agricultural waste wastes in several types of plastic wood has significantly improved the bending and tensile properties. Among them, the bagasse stem has a significant advantage over other lignosullose materials. The use of polymer waste and agricultural waste using nano-silica has shown the best results of resistances. In general, the results have shown that the use of agricultural fiber wastes as reinforcers in plastic wood polymers have the expected mechanical properties.
