Chemical conversion
mohammad najafianashrafi; Payam Moradpour; Ahmad Jahan latibari; Hamidreza Edalat
Abstract
Poly vinyl acetate (PVAC) adhesive is one of the most important adhesives in wood and furniture industry, which has many advantages such as low cost, environment friendliness and non-toxicity. However, it has some disadvantages such as low water resistance and poor boning strength. In this study, the ...
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Poly vinyl acetate (PVAC) adhesive is one of the most important adhesives in wood and furniture industry, which has many advantages such as low cost, environment friendliness and non-toxicity. However, it has some disadvantages such as low water resistance and poor boning strength. In this study, the effect of nano silica (NS) on the properties of poly vinyl acetate adhesive was investigated. The adhesive formulation with different NS contents (2, 3 and 4%) was added to the PVAC. The structure of the prepared adhesive samples was studied by FT-IR and XRD. We used the wood of Acer tree (Acer cappadocicum) to make joints in this study. Two standards of D882 and ASTM D905 were used for tensile and shear tests, respectively. Results showed that adding NS to PVAC enhanced the tensile strength of films. For example, the tensile strength of prepared films was increased by 30% after adding 4% of NS. Moreover, shear strength test showed that NS up to 3% can improve PVAC bond strength. Viscosity results showed that increasing the weight of NS up to 3% to PVAC glue lead to an increase following a decrease in the viscosity
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.
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.
Zahra Gholami; Mohammad Azadfallah; soheila izadyar; Mehdi Roohani
Abstract
In this research, deinked pulp (DIP) was modified with carboxymethyl cellulose (CMC) in order to introduce more charged groups on the surfaces of fibers which leads to improve strength properties. Modification of the pulp was conducted at mild reaction temperature conditions of 85, 95°C and 120°C ...
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In this research, deinked pulp (DIP) was modified with carboxymethyl cellulose (CMC) in order to introduce more charged groups on the surfaces of fibers which leads to improve strength properties. Modification of the pulp was conducted at mild reaction temperature conditions of 85, 95°C and 120°C at 60 and 90 minutes, and under sever conditions of 120°C for 120 minutes in the presence of calcium chloride as electrolyte. The drainage time, water retention value (WRV), tensile strength, burst strength, brightness and opacity of CMC-modified pulps were measured and compared with corresponding values of blank (untreated) pulp and CMC-treated pulps as conventional treatment. The results indicated that tensile strength and burst strength of CMC-modified pulps were improved in comparison with unmodified pulps. The behavior of pulps was different in terms of optimum reaction condition. However, no significant changes were observed for optical properties of CMC-modified pulps. Water retention value of CMC-modified pulps decreased unexpectedly in some conditions.
Management and Economics wood
Mysam Khalilian Shalamzari; Mahammad ali Sadat nia; Hamid reza Pirayesh
Abstract
The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, ...
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The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, were used. The mechanical and the chemical properties as well the color variations were measured on taken samples. The results showed that the long storage durations of bagasse significantly decreased the quality of row materials observed in hand sheet tensile and fold strengths. The results illustrated that the amount of Lignin and extractives increased (44 % in lignin and 32% in extractives amount respectively) and also decrease in amount of cellulose and hemicellulose was found (10% for cellulose and 43% for hemicellulose) during 5 years storage in yard. According to the results, there was an obvious difference in L and a color index of 5 years old bagasse in comparing with those of fresh bagasse. Finally it can be drawn that the use of discorded and weathered bagasse could cause the loss in the final products quality which means more chemical treatment for bleaching and more using long fiber in paper making process.
Amir Zamani; Ahmad Jahan Latibari; Aghang Tajdini; Abolfazl Kargarfard
Abstract
In this investigation, the surface chemical properties of the beech wood layers were characterized and the impact of drying condition on the strength of the bond was examined. Defect free beech logs were harvested and then the layers were prepared. The moisture content of the specimens were adjusted ...
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In this investigation, the surface chemical properties of the beech wood layers were characterized and the impact of drying condition on the strength of the bond was examined. Defect free beech logs were harvested and then the layers were prepared. The moisture content of the specimens were adjusted at 30, 40 and 50% (dry basis) and then the specimens were air dried under the environment of 30% relative humidity and 21ºC to reach the equilibrium moisture content of about 10% (dry basis). The pH and buffering capacity of the surface layer and the layer 0.5 mm underneath the surface were measured. The dried specimens were bonded using urea-formaldehyde resin and the tensile strength and wood failure were measured using relevant ASTM method. The results showed that as the moisture content prior to air drying was increased, the tensile strength was reduced, but the effect of this variable on tensile strength was not statistically significant. However, the effect of moisture content on wood failure was statistically significant at 99% significance level. The effect of the pH of the under layer on both tensile strength and wood failure was statistically significant at 95%. As the moisture content of the wood increased, the pH of the surface layer increased and the strength of the bond with urea-formaldehyde resin was deteriorated. At higher initial moisture of the wood, the alkaline buffering capacity of the surface layer was lower and its effect of the strength was not statistically significant, but it was significant on wood failure at 99% level. The alkaline buffering capacity of under layer was also changed and statistically affected the bond strength and wood failure at 95% level. The higher alkaline buffering capacity of the under layer adversely affected the tensile strength of the bond. The lowest acid buffering capacity was measured from specimens with 40% initial moisture content and as the acid buffering capacity was increased, the tensile strength was reduced and the wood failure was higher. The impact of surface layer acid buffering capacity on tensile strength was on statistically significant, but on wood failure was statistically significant at 99% level.
Vahid reza ُSafdari; Nima Eskini; Ajang Tajdini; Vlima Bayramzadeh
Abstract
Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: ...
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Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: inside of soil and exposed one can reveal effects of soil erosion on wood anatomical properties of root. So many roots and barks of trees in inside of soils and exposed have been sampled and many micro-sections prepared by microtome and anatomical properties were investigated. Results showed that wood roots under soil conform of one row of late-wood and by exposing the lumen area of tracheids in early-wood and late-wood were decreased and the cells appear thicker and late-wood portion increased. The axial parenchyma inclusion of dark resins in exposed roots observed frequently. Meanwhile by exposing of roots the thickness of bark decreased and the thickness of phloem and periderm in exposed root is not as wide as normal roots.
Sina Modirrahmati; Ahmad Jahan-Latibari; Mansor Minaei
Abstract
The influence of nanoclay addition on the strength properties of HDPE/ Wheat straw powder Composite was investigated. Composites compounds were produced using 73%HDPE, 25% wheat straw powder and 2% MAPE and three amounts of nanoclay (1, 2, and 3% of composite compound). First, HDPE and nanoclay was melt- ...
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The influence of nanoclay addition on the strength properties of HDPE/ Wheat straw powder Composite was investigated. Composites compounds were produced using 73%HDPE, 25% wheat straw powder and 2% MAPE and three amounts of nanoclay (1, 2, and 3% of composite compound). First, HDPE and nanoclay was melt- mixed and after cooling, the extrudate was milled to fine granules. This granules were then melt compounded with pre-weighted amount of wheat straw powder and MAPE followed by injection moulding to produce test specimens. The flexural, tensile and impact strength were measured. The results showed that the addition of nanoclay to the composite improved flexural strength and modulus, tensile strength and modulus. However the notched Izod strength was reduced.
Sina Modirahmati; Ahmad Jahan Latibari; Amir Nourbakhsh; Mehran Roohnia; Mansor Minaei
Abstract
The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- ...
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The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- melting of nanoclay and polypropylene was used to add nanoclay to the composite mixture. Pre-mixed nanoclay/ polypropylene was melt-mixed with OCC fibers and MAPP and then test samples were made using this compound. The results revealed that addition of nanoclay to polypropylene/OCC fiber composite reduced flexural strength , tensile strength and notched Izod impact strength, but the flexural modulus and tensile modulus of final composite were improved significantly. The influence of nanoclay addition on flexural strength and tensile modulus of composite was statistically significant at 99% level whereas its effect on tensile strength was statistically significant at 95%. However, the effect of nanoclay on both flexural modulus of elasticity and impact strength was not statistically significant. The addition of nanoclay to the composite reduces the bonding between polypropylene and OCC fibers. In the case of notched Izod strength, nanoclay particles generated stress concentration point within the composite structure initiating easier failure. Water absorption after 2 and 24 hours immersion was reduced.
Alireza Asgari; Ahmad Jahan latibari; Seiad Javad Sepidedam
Abstract
The impact of Multi Wall Carbon Nano Tubes addition on mechanical properties, water absorption and thickness swelling of polypropylene/old corrugated container (OCC) fiber composites was investigated. Polypropylene/ OCC fiber composite was prepared using 30% OCC fiber, 67% polypropylene and 3% MAPP. ...
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The impact of Multi Wall Carbon Nano Tubes addition on mechanical properties, water absorption and thickness swelling of polypropylene/old corrugated container (OCC) fiber composites was investigated. Polypropylene/ OCC fiber composite was prepared using 30% OCC fiber, 67% polypropylene and 3% MAPP. Three levels of multi wall carbon nano tubes (1, 2, 4% based on the weight of fiber/polypropylene/MAPP mixture) were added. Composite compound was prepared using a Haake mixer and the test samples were extruded. The results of strength measurement indicated that when 1 or 2% multi wall carbon nanotubes were added, Izod impact strength and flexural strength improved. Higher flexural modulus of elasticity was reached as either 2 or 4% multi wall carbon nano tubes was added. The performance of 4% multi wall carbon nano tubes on flexural modulus of elasticity was superior. Lower water absorption and thickness swelling levels were observed, as 1% multi wall carbon nano tubes was added.
Pulp and paper
Ahmad Samariha; Jafar Ebrahim poor tasmani; Alireza Khakifiroz
Abstract
This research was performed to investigate the properties of CMP pulp from rape straw. Samples of Colza straw was prepared from a farm located in the vicinity of Babul. Chemo mechanical Pulping process was employed using the 20 % cooking liquor of Mazandaran pulp and paper mill (Sodium Sulphite) based ...
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This research was performed to investigate the properties of CMP pulp from rape straw. Samples of Colza straw was prepared from a farm located in the vicinity of Babul. Chemo mechanical Pulping process was employed using the 20 % cooking liquor of Mazandaran pulp and paper mill (Sodium Sulphite) based on the dry weight of colza straw. Cooking time and temperature were adjusted at 30, 40 and 50 minute and 170 degree centigrade, respectively. Pulps were refined up to 300± 25 CSF by using PFI Mill refiner and 60 g/m2 hand sheets were made from each sample of pulps. The strength indices of hand sheets were measured using TAPPI standards. The results showed that strength indices like Tensile strength, Tear strength, Burst strength, Breaking length and Stiffness increased as the pulp yield decreased.
Pulp and paper
Behzad Kord
Abstract
This study is for identifying of the effect of refining intensity on pulp and paper properties made from eucalyptuswood. For this purpose three normal eucalyptus camaldulensis spp trees were randomly cut down from Shastkolateh Experimental Forest located in Gorgan. From each tree, one disk ...
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This study is for identifying of the effect of refining intensity on pulp and paper properties made from eucalyptuswood. For this purpose three normal eucalyptus camaldulensis spp trees were randomly cut down from Shastkolateh Experimental Forest located in Gorgan. From each tree, one disk with 50cm thickness from breast height were selected for pulp making. Then disks converted to chips by chipper, and the chips were cooked by kraft process, the cooking conditions were as following effective alkali 20%, sulfidity 25%, tempreture 190 0C and Time 90min. After cooking and pulping process, the pulp refined with PFI Mill in 5 different intensity with 0 rpm, 500 rpm, 1500 rpm, 2500 rpm and 3500 revelutions. Then, papermaking and measuring the paper properties such as freeness, tensile strength, tear strength, burst strength and density were done. Then data were statisticaly analysed. The results indicated that, there are significant difference between pulp and paper properties made of eucalyptus camaldulensis spp wood with 5 different refining intensity in 95% confident level. As increasing of refining intensity and refining revolutions, freeness and tear strength of paper decreased but tensile strength, burst strength and density of paper incrased. However, the highest value of freeness and tear strength of paper related to refining intensity with 0rpm revelution (without refining) and highest value of tensile strength, burst strength and density of paper related to refining intensity with 3500rpm revelution
Pulp and paper
Mohammad Talaei poor
Abstract
The effect of refining of recycled pulp on the optical, physical and mechanical properties of paper was investigated.The results showed that, except tear strength, all of mechanical strength of paper significantly increases by refining.While, by refining of recycled pulp the brightness increases but ...
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The effect of refining of recycled pulp on the optical, physical and mechanical properties of paper was investigated.The results showed that, except tear strength, all of mechanical strength of paper significantly increases by refining.While, by refining of recycled pulp the brightness increases but the opacity decreases.Also, caliper and roughness of paper decreases.Refining of recycled pulp result in increasing Porosity.
Omid Ramazani; Ahmad Jahan latibari; Mohammad mehdi Faezipoor; Ali akbar Enayati; Sayed mehdi Manzor alajdad
Abstract
Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables ...
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Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables influences the apparent density of paper, in this study, the influence of OCC pulp freeness, and drying conditions are investigated. The influence of three freeness levels of 350,450, and 550 CSF, drying under strain and unstrained, drying temperatures of 100, 150, 200 C and drying pressure of 7 and 10 kg/cm2 are studied. The relationship between paper making variables and apparent density is developed. All measurements of apparent density were analyzed using Minitab 15 and regression model between independent variables was calculated. The results showed that both pulp freeness and drying temperature had the highest impact on apparent density and both factors increased the apparent density. The response of apparent density of the hand sheets dried at 200 ◦C varied considerably and was analyzed thoroughly. Higher pressure increased apparent density of the sheets. The combined effect of variables is also considered. The combined effect of pulp freeness and drying temperature caused lignin softening and delamination. However, the influence of increasing the drying pressure for unrefined and less refined pulp is not significant. Furthermore, for unstrained drying, the influence of freeness on apparent density was more than strained drying. Manufacturing of more desirable quality papers would be possible considering the obtained results and the effect of Apparent Density on paper strength properties.
