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
Foroogh Dastoorian; Faezeh Farhadi; Fahimeh Hoseinzadeh; majid zabihzadeh
Abstract
The present study was done with the aim of investigation of the effect of heat treatment on chemical and physical properties of Iranian beech and Velvet maple. Results of spectroscopy showed that heat treatment led to decrease of hydroxyl groups which became more sensible with increasing temperature ...
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The present study was done with the aim of investigation of the effect of heat treatment on chemical and physical properties of Iranian beech and Velvet maple. Results of spectroscopy showed that heat treatment led to decrease of hydroxyl groups which became more sensible with increasing temperature up to 175oC. Treatment at 190oC led to an increase of hydroxyl group comparing to the control ones. Increasing cellulose crystallinity, decreasing the hemicellulose content, increasing the lignin ratio, degradation of syringyl lignin and increase the condensation reaction of lignin was also obtained from spectroscopy. Results of water absorption tests also showed that heat treatment caused decreasing of water absorption. The water repellent and anti-swelling efficiency for both species showed that heat treatment at 160oC didn’t improve the water repellency and dimensional stability however treatment at 190oC led to decrease of water absorbance specially in beech. In total, the effect of heat treatment on anti-swelling efficiency in beech was more considerable comparing to acer, which can be explained by higher weight loss after heat treatment.
Composite wood products
Maryam Ghorbani; null null; farhad fooladian
Abstract
The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties ...
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The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties of composite made from sunflower stem flour-polypropylene. Thermal modification of sunflower stems was done at temperatures of 160, 180 and 200°C for 30 minutes and mixed with polypropylene in ratio of 30wt%. Test samples were prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. FTIR spectroscopy of sunflower stem flour confirmed the chemically changes due to thermal modification. More integration and uniform distribution, and less cavities were observed in the scanning electron micrographs of failure surface. The removal of hemicellulose of sunflower stem flour improved the thermal stability of composite, which thermal gravimetric analyzer (TGA) confirmed it with increasing in modification temperature up to 180°C. Modification at 200°C decreased thermal stability compared to other temperatures. Thermal modification leads to significant decrease in water absorption and improvement in bending and tensile properties due to hemicellulose degradation, increasing the crystallinity, loss of polarity, increased compatibility between the two phases of composite and uniform distribution of fillers in polymeric matrix. Notched impact strength of modified composites decreased due to better adhesion between lignocellulosic filler and polymer that facilitate the crack development along the interface.
Pulp and paper
Noradin Nazaneghad; seid najeh Mosavi; Seid Majid Zabihzadeh
Abstract
Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of ...
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Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of different treatments. Cationic starch is effective treatment for recycled fibers Promotion. In this study, the cationic starch of Tapioca and Corn, each at three different levels 0.5, 1 and 1.5 % and comparison with samples (without cationic stretch). Hand sheets with a grammag of 120 g/m2 were made and their strength properties were measured. As well as, the absorption rates of two kinds of starch on the pulp were calculated using the Acid- Phenol method. The results indicated that the use of 1.5% of Tapioca starch and 1% Corn starch had an optimum effect in increasing the strength of the produced paper. Concerning the comparison of these different types of starch, the tapioca starch was more effective than the corn starch.
Physics and Mechanical Wood
foroogh dastoorian; Mohammad Layeghi; Ghanbar Ebrahimi; Mehdi Tajvidi; Seid Majid Zabihzadeh
Abstract
In the present study, creep rupture behavior of a bagasse fiber- polypropylene composite was investigated. Two accumulated damage model (EDRM and Wood) and an energy based failure model (R-W) were adopted to describe the load duration influence on the studied composite. Results have shown that at very ...
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In the present study, creep rupture behavior of a bagasse fiber- polypropylene composite was investigated. Two accumulated damage model (EDRM and Wood) and an energy based failure model (R-W) were adopted to describe the load duration influence on the studied composite. Results have shown that at very high stress levels, the EDRM and Wood models underestimated and overestimated the time to failure than static value respectively. This was attributed to the difference between application of static loading and creep loading. Findings indicated that the all three models were able to describe the creep rupture behavior of the studied composite and among this; the Wood model has shown a better fitting with experimental data, statistically. Based on findings in the present research, it can be concluded that the R-W model was more conservative in predicting time to failure in comparison with the two other models, and the reason can be attributed to the difference between failure criteria in energy based models and accumulated damage models. Results also showed that with increasing stress levels, the secondary stage of creep will shorten and at high stress level, the tertiary stage of creep will be more dominant
Pulp and paper
Maryam Alipoor; Ghasem Asadpur Atouei; Seaid Majid Zabihzadeh; Zohreh Ghazvini
Abstract
With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile ...
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With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile and burst indexes) properties. Pre-treatment was accomplished with pure hot water and alkaline solutions (NaOH) at three levels of 0.5, 2 and 3.5 percent too. Pre-treated populous deltoids wood chips and control (chips without washing) were converted to pulp by CMP process. The results of this research indicated that the pretreatment of populous deltoids wood chips with hot water and also alkaline solutions caused wood chips mass and using of these treated chips for pulping caused pulp yield and brightness increscent, pulp strength reduction and also energy consumption increscent. . Removing of some part of chips hemicellulos have negative effect on the pulp refinability and cause pulp strength reduction.
Pulp and paper
Mohtaba Goli; Majid Zabihzadeh; Saeed Mahdavi; Hassan Sadeghifar
Abstract
The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried ...
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The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried to calculate the moisture content. Wood composition percentages for CMP pulping was 40% poplar, 30% maple, 7.5% oak, 7.5% alder, 7.5% willow, and 7.5% Persimmon. In order to remove heavy metal ions of pulp, the chelating was carried out with DTPA. TCF Bleaching carried out by 3% H2O2 and 2.5% NaOH based on dry weight of pulp with initial brightness of 44.6% ISO. Pulp bleaching was done in two stages, before and after the refining by laboratory PFI mill beater. Finally, handsheets were made from the RB and BR treated pulps and the sheet properties were evaluated according to TAPPI test methods. The results showed that BR treatment increased tensile, burst, tear indices, brightness, scattering coefficient, and density, but reduced yellowing, opacity, and light absorption coefficient. The results confirmed the conventional method of CMP pulp treatment (BR) in MWPI.
Composite wood products
ghasem asadpour; seyyed majid zabihzadeh; Maryam Ghorbani; mahmoud davoudi
Abstract
Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, ...
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Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, 30 and 40%. Test samples prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. According to the results, bark flour increased water absorption, tensile and bending modulus. High proportion of bark fillers declined mechanical strength. Thermal modification significantly improved physical and mechanical properties of composite. Using lignocellulosic material flour bark hornbeam, tensile modulus and flexural modulus of composite material background had the highest improvement. In comparison between mechanical properties, impact resistance by adding flour bark had the greatest decrease. Thermal modification by increasing the crystallity, hemicellulose degradation, loss of polarity, increased compatibility between the two phases and uniform distribution of bark fillers in polymers, increased mechanical resistance.
Zahra Ebrahimi; Hossein Kermanian; Omid Ramazani; Majid Zabihzadeh
Abstract
This research was carried out to compare the paper properties from rice straw applying sodium and potassium based Chemimechanical pulping processes. Cooking conditions in potassium based pulping were adjusted as; potassium sulfite 6, 8, 10 and 12%, potassium hydroxide 3, 4, 5, 6, 8 and 12% on oven dry ...
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This research was carried out to compare the paper properties from rice straw applying sodium and potassium based Chemimechanical pulping processes. Cooking conditions in potassium based pulping were adjusted as; potassium sulfite 6, 8, 10 and 12%, potassium hydroxide 3, 4, 5, 6, 8 and 12% on oven dry weight of rice straw, impregnation time; 30 minutes, liquid to rice straw ratio of 7:1, cooking time 30 and 60 minutes and cooking temperature 130, 150, 160, 165 and 170 oC. In sodium- based pulping, cooking conditions were selected as; sodium sulfite 6 and 8%, sodium hydroxide 3 and 4 % on oven dry weight of rice straw, impregnation time 30 minutes, liquid to rice straw ratio of 7:1, cooking time 30 minutes and cooking temperature 130 and 150 oC. The selected treatment in potassium based pulping showed the average total yield of 65.19 and reject of 4.22% and in sodium based pulping showed the average total yield of 69.75 and reject percent of 3.68. After refining the selected pulp to reach the freeness of 300±25 ml CSF, 60 g/m2 hand sheets were made and physical, mechanical and optical properties were measured. Results showed that the tensile strength index, breaking length and apparent density of paper made from potassium based process was similar to paper made from sodium based process. The papers made from potassium based process had higher burst strength index and brightness compared to sodium based process and papers made from sodium based process had higher tear index and higher K/S values than potassium based paper.
