حبیب الله خادمی اسلام

In this study, the possibility of making a composite from bagasse was investigated. Bagasse-polypropylene fiber samples with different bagasse percentages (15, 25, and 35%) and coupling agent (0, 1.5, and 3%) were made, and their mechanical properties were examined. The results showed that with an increase in bagasse fibers, the flexural strength and tensile modulus did not change significantly, but the modulus of elasticity and energy at the breaking point decreased significantly, but the tensile strength increased. The results of the impact resistance test showed that although the impact resistance decreased and increased slightly with an increase in the percentage of bagasse fibers and coupling agent, this amount of decrease and increase was very small and insignificant, and the results of this test were random and unrelated to the increase in raw materials. However, in the impact resistance test without a notch, a significant difference in the decrease in impact resistance was observed with an increase in fibers and its increase with an increase in coupling agent. Overall, all measured engineering properties in this study improved, except for impact resistance, which decreased with an increase in fibers. It is suggested that to improve the engineering properties of this type of composite, the bagasse percentage and coupling agent should be increased up to 30% and 3%, respectively.

The use of various pretreatments, including the torrefaction process, in order to increase the efficiency and optimize the consumption of fuel briquettes, have attracted a lot of attention in recent years. Therefore, in this research, torrefaction pretreatment at 180 ºC temperature was used to modify bagasse biomass. In addition, lignin binding agent was used at levels of 2, 5 and 10%. Fuel briquettes weighing 30 grams were prepared using a manual briquetting machine. The physical, resistance and thermal characteristics of the resulting briquettes were investigated. The results showed that torrefaction pre-treatment by increasing the volumetric density of the resulting briquettes and increasing the amount of fixed carbon up to about 50% was able to increase the heating value of the briquettes up to about 10%, on the other hand, this process led to a decrease in the compressive strength of the resulting briquettes, which is used lignin as a binding agent could compensate a significant amount of this resistance drop. The results showed that the number of volatile substances of briquettes was reduced by 9% with torrefaction pre-treatment, which has a significant effect on reducing the pollution of these briquettes. In the study of the effect of lignin, it was also observed that with the increase in the consumption of lignin, the density and calorific value also increased. In general, the results of this research show that the use of lignin binding agent together with torrefaction pre-treatment can make possible the production of high-quality fuel briquettes from bagasse.

This study uses soda lignin to modify it with furfural as adhesive on the physical and mechanical properties of plywood Poplar wood. Producing plywood, pure Lignin (L.100%), lignin-furfural 30% (L.70-F.30), lignin- furfural 60% (L.40-F.60) were used as the adhesive at three different levels ( 120 140 160gm2) accompanied with ammonium chloride (1%) as the hardener and wheat flour (30%) as the filler based on the dry weight of the adhesive. Plates made with urea formaldehyde resin at 160 g/m2 were produced as control samples. characteristics of adhesives included solid material percentage, viscosity, specific weight and PH were measured. After producing the laboratory boards, the physical and mechanical properties of samples, such as thickness swelling after 2 and 24 hours of being soaked in water, shear strength, modulus of rupture, and modulus of elasticity were measured. The results indicate that independent and interactive effects of adhesive and its consumption level on the physical and mechanical properties of plywood are not statistically significant. And in all cases, the control boards had better properties than the lignin adhesives

Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important topic. In this study, the possibility of the production of poly lactic acid (PLA)-rice husk composite with acceptable properties, and also the effect of using flame retardant mineral fillers of aluminum three hydrates (ATH) and magnesium di-hydroxide (MDH) on physical and thermal properties of the produced composite were investigated. Results indicated that the density of PLA-rice husk composite was higher than petroleum-based polymers composites (PP/HDPE-rice husk composites); and flame retardant mineral fillers addition led to an increase in the composite density. Also, flame retardant mineral fillers addition decreased the composite water absorption and thickness swelling, in a way that they were comparable with petroleum-based polymers composites. Results of thermal gravimetric analysis (TGA) showed that flame retardant mineral fillers addition also decreased the temperature of the composite weight loss curve peaks, and the weight loss rate toward temperature rising.

The aim of this study was to investigate the effect of coating Populus nigra with silica nanoparticles on some performance parameters. Wood samples of P. nigrawere were coated with a combination of silica nanoparticles (3%, 5% and 7%) and zycosil by spin coating method and the obtained results were compared with controls of A. alba and P. nigra. Structural properties of wood samples were investigated by SEM and FTIR tests. Performance properties of wood samples, including water absorption, contact angle and density were investigated. The results showed formation bonds between silica nanoparticles and zycosil. Coating wood samples with silica nanoparticles in the concentrations of 5% and 7% in combination with zycosil decreased water absorption compared to P. nigra control (P<0.05). The wood samples coated with nanosilica and zycosil had a higher contact angle and density compared to P. nigracontrol (P<0.05).

In this study, acidified Luffa (AHS@L), by sulfonic acid, as an effective and biodegradable solid acid catalyst was produced. The synthesized catalyst was characterized by TGA, SEM, XRD and FTIR, and the results indicated that modified Luffa flour had an intense acidic property. The FT-IR analyze show a broad peak at 3400cm-1 that improve the acidification of the Luffa surface. Also the XRD analyze clearly show the change in the morphology of Luffa after acidification. The TGA analyze show us the heat resistance of the catalyst up to 245 ° C and the SEM images clearly showed that the catalyst surface was hydrated as a result of acidification. The synthesized catalyst was used to protect the amines in the N-tert butyl carbamate reaction under solvent-free conditions at room temperature. Different types of aliphatic and aromatic amines have been produced as related monocarbamates with excellent yields and short reaction times. This method was mild and selective and has advantages such as heterogeneous catalysis, low cost and catalyst recovery capability.

In this study, the effect of cellulose nanofibers and silicon nanoparticles on the properties of nanocomposites made with polyvinyl alcohol was studied and the physical, mechanical and morphological properties of nanocomposites were investigated. Samples were prepared by casting with different ratios of 0, 5 and 10% by weight. The morphology of nanocomposites was examined by scanning electron microscopy. Observations of water vapor permeability and water uptake by adding cellulose and nanoxide oxide nanofibers in pure polyvinyl alcohol control film and nanocomposite films with different compositions were significantly different from each other. Tensile strength of nanocomposites showed that increasing the amount of cellulose nanofibers and silicon nanoparticles increased the tensile strength and the percentage of elongation increased with the addition of cellulose nanofibers and silicon nanoparticles decreased. The results of the present study show that the addition of small amounts of nanocellulose fibers and silicon nanoparticles strengthens the polyvinyl alcohol polymer and improves the physical and mechanical properties and increases the performance of nanocomposites.

Abstract In this research, the effect of cellulose nanocrystals on the functional properties of wood cement composite panels has been investigated. Variable factors in this research are the percentage of nano in (five levels of 0, 0.1, 0.2, 0.5 and 1%), the weight of cement and also the ratio of mixing wood chips with cement in three levels (1 to 3, 1 To 3.5 and 1 to 4) dry weight of cement. In this research, poplar wood and Portland cement type 2 have been used as fixed agents. In total, 15 treatments and 3 replicates of each treatment were made. Preparation of sample in accordance with the standard (DIN / EN 634) and measurement of physical and mechanical properties including flexural modulus, modulus of elasticity in accordance with the standard (DIN / EN 310), internal adhesion in accordance with the standard (DIN / EN 319), thickness swelling after 2 and 24 hours of immersion in water was performed according to the standard (DIN / EN 317). Increased cellulose nanocrystals improved physical and mechanical strength. SEM microscopic images were taken from the samples to examine the microstructural properties of the composite. In the pictures, it was found that by adding cellulose nanocrystals, we see an improvement in the disintegration of nanocomposite materials and as a result, an increase in mechanical and physical properties.

This study uses the Lignin-Glyoxal adhesive to replace chemical resins with environmental compounds producing plywood. producing plywood, pure Lignin (L.100%), lignin- glyoxal 15% (L.85-G.15), lignin-glyoxal 30% (L.70-G.30) and Urea-formaldehyde (control) were used as adhesive at 160 gr/m2 level. Accompanied with ammonium chloride (1%) as the hardener and wheat flour (30%) as the filler based on the dry weight of the adhesive characteristics of adhesives included solid material percentage, viscosity, specific weight and PH were measured. After producing the laboratory boards, the physical and mechanical properties of samples, such as thickness swelling after 2 and 24 hours of being soaked in water, shear strength, modulus of rupture, and modulus of elasticity were measured. In addition, the groups and bonds in the pure lignin and lignin-gloxal adhesives were identified by Fourier Transform Infrared (FTIR) spectroscopy. The results indicated that the independent effect of adhesive type on the thickness swelling of plywood after 2 and 24 hours was significant. Although the results suggest that modifying the lignin would improve the plywood in all cases, the control boards had better featurers than those made with the Lignin-Glyoxal adhesive.

In this study, the effect of nano-wollastonite on physical, mechanical and morphological properties of composites made of bagasse and gypsum was investigated. The mixing ratio of sugarcane to gypsum pulp at three levels (80:20, 70: 30 and 40: 60%) and nano-wollastonite at three levels of zero, 3 and 7% were considered as the variables of this study. The thickness of the test boards was 16 mm cake density of all boards was considered to be 1.10 gr/cm3. Then the mechanical and physical properties of the specimens including modulus of rupture, modulus of elasticity, internal bonding, water absorption after 2 and 24 hours immersion and density of boards according to DIN-EN-634 and fire resistance (weight loss percentage) according to ISO 11925 Were measured. In this study, a thermocouple and a flask were used to measure the hydration heat. Microscopic images (SEM) were obtained from the fracture surface of the specimens to investigate the common boundary between bagasse-gypsum and nano-dispersion. The results showed that with increasing bagasse mixing, the modulus of rupture, modulus of elasticity and internal bonding decreased and water absorption and weight loss percentage of boards exposed to fire increased. Application of nano-wollastonite up to 7% improved all mechanical and physical properties of composites. Also, microscopic imaging (SEM) showed that the optimum level of nano-wollastonite can fill vacant voids due to gypsum hydration and create a uniform structure.

The aim of this study is to evaluate the dynamic and static of elastic properties of Fir wood joints. For this purpose conventional joints in woos industry including dovetail, tongue and groove beech wood (Abies alba.) joints with polyvinyl acetate (PVA) and cyanoacrylate (CA) adhesives were used. Dimensions of research samples were determined 24×50×360 (mm) according to international standard (ISO No.3129), and the results indicate that the effects of joint type, adhesive type, joint size, and also retrospective joint size became meaningful at 5% level in dynamic and static tests. As the length of groove and height of dovetail and length of dowel increased in the joints, dynamic and static elasticity modules increased, and in terms of changes in elasticity modules of the research. Elasticity module for dovetail joint, as a result of the shape, having a homogenous joint texture, and also lack of extended adhesive line in the joint, is closer to un jointed samples (control group). Also cyanoacrylate adhesive improved elasticity features of samples compared to polyvinyl acetate adhesive as a result of higher tension resistance and faster coagulation. The results of the Student's t-test indicate that there exists a not significant difference between the mean of dynamic and the mean of static modulus of elasticity, not significance at 5% level and The Pearson correlation test indicate that the dynamic and static modulus of elasticity of the samples are significant at 5% level and are of positive correlation(+.0958) .With regard to the correlation of the results of dynamic and static tests, methods for non-destructive dynamic investigation may be regarded as appropriate alternatives to destructive static tests, in order to assess and classify woods.

Abstract Effects of temperature, cellulose Nano fibers and Nano clay particles on mechanical, physical and morphological properties of biodegradable composites made of recycled thermoplastic starch biopolymer and regular mixed industrial sawdust are investigated. To this aim Cellulose Nano Fibers and Nano Clay particles were selected to be 0, 3 and 5 weight percent and were added to prepared biodegradable composites by using internal mixer and samples prepared by injection molding. Mechanical properties including tensile modulus and strength, flexural modulus and strength were extracted at temperatures ranging from 23 ºC to 80 ºC. Impact test and water absorption and thickness swelling were also performed according to related standards. Results show that elevating the temperature drastically reduce mechanical properties. Nano Clay addition results in better mechanical properties except for impact and water absorption and thickness swelling are improved. Using 5% Cellulose Nano Fibers improves mechanical and morphological properties better than 3% addition. Dynamic mechanical thermal analysis revealed Nano composites samples with 5% Nano Clay and Cellulose Nano Fibers has higher storage modulus and glass transition temperatures in compare to pure composite samples. This Nano particles can be successfully used to improve properties and performance except for fracture resistance.

The aim of this study is to evaluate the dynamic and static of elastic properties of beech (Fagus orientalis) wood using conventional joints in woos industry including dovetail, tongue and groove beech wood with cyanoacrylate (CA) adhesives. Dimensions of experimental samples were determined 24×50×360 (mm) according to international standard (ISO No.3129). The results indicate that the effects of joint type, joint size, and retrospective joint size became meaningful in dynamic and static tests (p<0.05). Elasticity module for dovetail joint due to the shape, homogenous joint texture, and lack of extended adhesive line in the joint is closer to unjointed samples (control group). Based on the Student's t-test and Pearson correlation test, dynamic and static elasticity modulus had statistically significant positive correlation (p<0.05). Regarding to the correlation of dynamic and static tests, methods for non-destructive dynamic investigation may be used as appropriate alternatives to destructive static tests for assessing and classifying the woods.

In this study, the possibility of three-layered oriented strand board production from hornbeam (Carpinus betulus L.) wood was evaluated. Two levels of press time (6 and 8 minutes) and three levels of press temperature (180˚C, 200˚C and 220˚C) were applied and 12 mm thick laboratory boards were made from hornbeam wood. The strands on the surface layers were aligned in the long direction of the board and the middle layer strands are cross aligned to the surface layers. In all treatments, board targeted density of 0/7 g/cm3 and mat moisture content of 7% and phenol-formaldehyde resin (PF) content of 7% based on the oven dry weight of the strands were kept constant. The mechanical and physical properties of the boards were measured as defined in relevant European standards test methods EN 300. The internal bound (IB) and thickness swelling (TS24) of boards were significantly improved as the press time increased from 6 to 8 minutes. The modulus of rupture (MOR) and internal bound (IB) and thickness swelling (TS24) were significantly improved as the press temperature increased from 180˚C to 220˚C. Overall results showed that the highest MOR and IB and the lowest TS24 were achieved at 8 minutes press time and 220˚C press temperature and all boards made from this mentioned conditions exceed the EN 300 standards for MOR, MOE, IB and TS24.

The effect of adding steamed and non-steamed fiber on physical and mechanical properties of the composites made of recycled polypropylene was investigated. Recycled polypropylene was used as a basic matrix at a 57% level, and poplar fibers were used at 180 °C for 1 h at a constant level of 40% in two forms: non-steamed and steamed. The ratio of steamed fibers to non-steamed fibers in composites was 100:0, 50:50, and 0:100, respectively. For all components, the coupling agent was maleic anhydride at a level of 3%. Mixing was done using an internal mixer at 180 °C and 60 rpm, and the samples were constructed by injection molding method. To investigate the effect of steam treatment on the fiber structure and crystallization, X-ray diffraction analysis and FTIR spectra were used. The results showed that the Steaming had no significant effect on resistance. But with steaming increased mechanical properties and physical properties of reduced.

In this study, the effects of mat moisture content and press temperature on physical and mechanical properties of three layered oriented strand boards were evaluated. Two levels of mat moisture content 7% and 10% and three levels of press temperature 180 ˚c , 200 ˚c and 220 ˚c were applied and 12 mm in nominal thickness laboratory boards were made from mixture of three clones of ten-year-old hybrid poplar ( populous euramericana vernirubensis, p. e. I-214, P. e. 561/41) while the strands on the surface layers are aligned in the long direction of the board and the middle layer strands are cross aligned to the surface layers. In all treatments, board targeted density of 0/7 g/cm3 and press time of 8 min and phenol-formaldehyde resin (PF) content of 7% based on the oven dry weight of the strands were held constant. The mechanical and physical properties of the boards were measured as defined in relevant European standards EN 300 for OSB/1 and OSB/2. Overall results showed that all boards made from above mentioned conditions exceed the EN 300 standards for MOR, MOE, IB and TS24. The bending properties (MOR and MOE) of boards were significantly improved as the mat moisture content increased from 7 to 10%. The highest MOR was achieved at 10% mat moisture content and 220 ˚c press temperature and the highest MOE was achieved at 10% mat moisture content and 180 ˚c press temperature. The Modulus of Rupture (MOR) and Thickness swelling (TS24) were significantly improved as the press temperature increased from 180 ˚c to 220 ˚c. The lowest TS24 was achieved at 7% mat moisture content and 220 ˚c press temperature and the highest IB was achieved at 7% mat moisture content and 200 ˚c press temperature.

This study aimed to investigation the effect of altitude on the bending creep behavior of hornbeam lumber (Carpinus betuluse). For this purpose, 9 hornbeam trees from three different altitudes (400, 800 and 1100m) from forestry projects of Meshelak Nowshahr were selected. 54 Clear samples were cut at mature wood in diameter breast height (DBH). The prepared samples (dimensions: 2.5 × 2.5 × 41cm) in a room at temperature of 20 C and relative humidity (RH) 65 % were conditioned. Afterward 3 weeks conditioning, relative creep and creep modulus using the four points flexural creep test in 20% maximum of deflection load were measured. Results indicated that, the effects of altitude on creep parameters was significant so as the maximum and the minimum relative creep observed in 800 and 400m altitudes, and the maximum and the minimum creep modulus observed in 400 and 800m altitudes, respectively. Analysis of variance (ANOVA) results indicated that the altitude has significant effect on the flexural strength and modulus of elasticity, which in turn caused decreasing the creep parameters.

A new kind of thermoplastic elastomer nano composite reinforced with nano cellulose fibers is reported. The first aim of this investigation was to study the interaction and dispersion of nano cellulose fiber into pebax matrix. This copolymer is Polyether – b – Amide thermoplastic elastomer which is synthetized from renewable resources, and its hydrophilic character allows it to interact with nano cellulose. The interaction and reinforcement effect of nano cellulose at 3 levels of nano cellulose (1%, 3% and 5%) were examined by Scanning electron microscopes (SEM), Fourier transform infrared spectroscopy (FTIR) and Mechanical tests (consists of young module, elongation at break and impact resistance). All results achieved from these tests were indicating appropriate effects of nano cellulose fibers for the strong interaction and close contact with polyamide phase of pebax polymer which caused high mechanical properties of nano composites. The young module and impact resistance of nano composite were significantly increased.

In this investigation, tensile and physical properties of polypropylene (as matrix)/wheat straw fiber/paper mill sludge (as filler) composites was studied. For this aim, ratio of wheat straw fiber/ paper mill sludge include (40/0, 30/10, 20/20, 10/30 and 0/40) were used in composite. Also, for better compatibility between the two phases3% of grafted MA as coupling agent was used. Mixing process was done in internal mixer, and then composite samples manufactured by injection molding. Result indicated that the tensile modulus of elasticity improved with increase of two fillers and also observed that the toughness of composite increased when compared to the pure PP, while the highest tensile modulus of elasticity related to the higher percentage of paper mill sludge. Tensile strength of composite decreased with adding of 40% wheat straw fiber, but with addition of sludge tensile strength increased significantly. With addition of straw wheat in PP matrix and its hydrophilic properties highest rates of water absorption and thickness swelling was observed. While with adding of sludge and less amount of Lignocellulosic materials, water absorption and thickness swelling were noticeably decrease with addition of binder and better connection with two phases.

In this study, the effect of beech acetylation on the adhesion of transparent paints nitrocellulose lacquer, asid catalyzed lacquer and Half Ppolyester was evaluated. For this purpose, some boards from internal part of beech (Fagus Orientalis) with a relative humidity of 12%, and 12 × 110 × 110 mm was ptepared and were treated by the two levels of acetic anhydride; with the acetylation intensity of 12/5% and 15/5%. Then the two processes were coated separately by transparent paint of nitrocellulose lacquer, asid catalyzed lacquer and Half Ppolyester. The FT-IR test was used to ensure the acetylation process. The results of bond resistance test showed that using of the radial direction compared with tangential direction, the bond strength was higher. Among the samples, the sample treated with acetylation of % 15/5 intensity in comparison with control samples and The lowest percentage of loss of adhesion was observed in control samples.
Survey results showed that the coating by use of nitrocellulose lacquer, Half Ppolyester compared with coating by use of nitrocellulose lacquer, asid catalyzed lacquer, has a higher adhesion strength.

In this study the possibility of nano- wollastonite usage in three level (0, 3 and 6 percent per dry weight of cement) and mixture ratios of lingo cellulosic materials to cement in three level 10:90, 20:80 and 30:70 on physical, mechanical and microscopic properties of composite made from kraft fibers was investigated. There were three replicatesfor each treatment and 27 experimental boards were manufactured totally. Specimens were prepared according to DIN- EN- 634 standard to measure mechanical and physical properties. Mechanical and physical properties including compression strength, interior bonding (IB), thickness swelling after 2 and 24 hours immersion into the water and density were measured. Micro- structural properties of composites were evaluated by SEM images.The results showed that compression strength, interior bonding and density increased by higher levels of nano- wollastonite content in the boards. By increasing of nano- wollastonite, dimensional stability was significantly improved in comparison to the control boards. SEM images showed the improvement of micro- structural boards by increasing the nano- wollastonite content.

In this paper, poly lactic acid (PLA)/ wheat straw fibers manufactured by twin screw extruder and molding compression have been studied. Wheat straw fibers were treated with trietoxymethel silane for better compatibility between two phases. Physical properties, tensile properties of the composites were analysis. The effect of the wheat straw fibers on the thermal properties of PLA has also been investigated in DSC experiments. The effects of silane treatment on the wheat straw fibers have been analyzed by FTIR. Scanning electron microscopy from samples surface were used for better study of water absorption and thickness swelling. Composites wheat straw fiber were treated shows signification lower water absorption and thickness swelling than composites PLA/ untreated wheat straw fibers. The lower amount of water absorption and thickness swelling occurred in the pure PLA. The existence crack and break occurred in the surface of PLA/ untreated wheat straw fibers composites after immersion in the water indicating higher water absorption and thickness swelling were in these samples. Wheat straw fibers were treated with silane due to better wetting and better linkage in the interfacial surface with PLA matrix showed higher tensile properties then PLA/ untreated wheat straw fiber composites. Differential scanning calorimeter test showed that with addition wheat straw fibers were treated to pure PLA the increased glass transition temperatures. The nucleating effect of wheat straw fibers, special treatment with silane cause to increased in the crystallization temperature composites than pure PLA which a positive effect showed on the degree of crystallization.

In this research, effects of concentration and time of silane treatment of rice straw flour on the morphology and mechanical strengths of rice straw flour/polypropylene composites were investigated. Tri etoxi vinyl silane (C8H18O3SI) made by German Merk Company with 98% purity in two concentrations of 5 and 10%, that each concentration had two immersion times including, 45 and 90 min for using treatment rice straw flour. Also the polypropylene, as a matrix with 65% wt% and MAPP as a coupling agent with 5 wt% were used for making all testing samples. For blending the internal raw materials, mixer Haake HBI system 90 machines and for making standard testing samples the injection molding were used. The results showed that composites including rice straw flour were treated with silane in the concentrations and times were recited to cause a significant increase in the bending and tensile properties (strength and modulus) in comparison with untreated composites. Also increasing the concentration and time of silane treatment among treated samples causes an increase in the bending and tensile properties. With attention to the results from morphological composites detected silane treatment cause to improve in adhesive interfacial surface of filler/ matrix, better dispersion filler in matrix and finals cause to be improved in the mechanical properties.

The present study is conducted to measure longitudinal growth stress and strain in the trees observed in the west part of Mazandaran region and also to compare the current phenomena in two tree species of Acer spp and Quercus Castaneifolia. The selected species are generally grown in the forests located in the highest point of the west part of Chalous River, i.e. southwest corner of Chalous city. Employing the single-hole method proposed by CIRAD, a French research center, the growth stresses index was determined according to the longitudinal growth residual strain value along the stem. The findings suggest that the stress and strain levels in these species are highly influenced by various features such as the age and diameter of the tree, the wood type (the reaction wood), the surface slope, and the wind. Moreover, as Acer spp and Quercus Castaneifolia are both extremely sensitive to the environmental elements, their recorded stress and strain values are relatively high that is clearly evident in the corresponding longitudinal growth residual strain. The average measured longitudinal strain in Acer spp and Quercus Castaneifolia were equal to 76 micron and 82 micron, respectively.