Chemical conversion
Khadijeh Khorram Margavi; Noureddin Nazarnezhad; Seyd Majid Zabihzadeh
Abstract
Background and objectives: Contamination in pulp mill wastewater and subsequently surface and underground water sources contamination with heavy metals is one of the most important problems which threatens the health of human being and other creatures. These metals penetrate and pollute the soil and ...
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Background and objectives: Contamination in pulp mill wastewater and subsequently surface and underground water sources contamination with heavy metals is one of the most important problems which threatens the health of human being and other creatures. These metals penetrate and pollute the soil and water. In this regard, this study investigated and determined heavy metals in the pulp mill wastewater before and after the wastewater treatment process. In this study the newspaper adsorbent was prepared and the efficiency of the adsorbent in the adsorption of copper, lead and cadmium metals was studied.Methodology: The adsorption experiments were performed to investigate the effect of the time of contact of the newspaper adsorbent and metals, and dose of the adsorbent. For this purpose, waste newspapers were first treated with sodium bicarbonate for one hour and then refluxed with 5% disodium hydrogen phosphate for 4 hours at 100 degrees Celsius and finally washed. Aqueous solutions with an initial concentration of 30 ppm for three metals lead, copper and cadmium were prepared by diluting the standard solution with distilled water. A specific amount of adsorbent was added to 10 ml of each solution and stirred in a mechanical shaker for specific times. Then they were filtered by filter paper purified and analyzed by atomic absorption spectroscopic device. After drying, the solid phase of the wastewater sample was subjected to acid digestion with nitric acid at a ratio of one to five. Then, the digested samples were analyzed with an atomic absorption spectrometer after washing.Results: The results of wastewater analysis in the basins before and after treatment showed that the amount of lead, copper and cadmium in the wastewater before treatment were 0.2129, 0.5983 and 0.0004 ppm, respectively. The amount of metals after the treatment process was 0.0469, 0.134 and 0.0001 ppm for lead, copper and cadmium, respectively. Also, according to the results, taking into account that the absorption rate was high and the same in the amount of absorbent used and the treatment times; the amount and time of the desired treatment in this experiment were not effective factors in the amount of metal absorption. Conclusion: The newspaper adsorbent is a good adsorbent for removing heavy metals from aqueous solutions due to high absorption capacity and low cost, which make the newspaper a potential adsorbent for the removal and wastewater treatment of the heavy metals. According to the results, the dosage and time of treatment with the newspaper adsorbent were not effective factors in metal removal.
Pulp and paper
Amir Hosein Ghasemi; Noureddin Nazarnezhad; Shaghaygh Rezanezhad; Seed Hasan Sharifi
Abstract
Background and objectives: Some medicinal herb extracts have the antibacterial capability. On the other hand, herb extract is one of the organic, natural, and environmentally friendly substances. In recent years, the production of environmental and safe packaging materials has attracted the attention ...
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Background and objectives: Some medicinal herb extracts have the antibacterial capability. On the other hand, herb extract is one of the organic, natural, and environmentally friendly substances. In recent years, the production of environmental and safe packaging materials has attracted the attention of scientists and industrialists. Paper is one of the biodegradable and less cost options for packaging in various industries, including the food industry. Also, the raw materials of paper can be modified and changed with different materials. As a result, paper fibers can be treated with herb extracts and used in the production of renewable papers with antibacterial properties.Methodology: In this research, thyme (Zataria Multiflora) was used for extraction. The thyme obtained from the research farm was dried and then powdered. Powdered thyme was treated via ultrasonication. In this method, two amplitudes of 40 and 60 amplitudes and three time levels of 3, 6, and 9 minutes were used for extraction. Then the papers were treated with herbal extract prepared in two amounts of 15 and 20% based on the dry weight of the paper by spraying. The antibacterial properties of the papers were investigated with Escherichia coli and Staphylococcus aureus bacteria. The chemical structure of materials extracted from the thyme extract investigated by fourier transform infrared spectrum (FTIR) analysis. Also, gas chromatography (GC-MASS) analysis was used to investigate the components of thyme extract. The optical properties of the paper, including brightness and opacity, and the strengths properties of the produced papers were measured by tensile, tear, and burst strengths.Results: The highest inhibition zone diameter in the treated paper with the thyme extracted by ultrasonic method was 20 mm in 40 amplitude and 9 minutes for Escherichia coli bacteria. Also, the highest inhibition zone diameter for Staphylococcus aureus bacteria was 14 mm in 60 amplitude and 6 minutes. According to the results of the papers analysis, the papers showed better antibacterial properties and higher inhibition zone against the Escherichia coli bacteria. The chemical compounds in the thyme extract including various substances such as hexane and furans. The most important chemical components that caused the antibacterial properties of the papers is carvenone, which was observed in the thyme extract. The results of the strength test of the treated papers showed that the sample of the thyme extracted by the ultrasonic method at 40 amplitudes, 3 minutes, and the 20% consumption amount based on the dry weight of the paper has the highest tensile and burst index. As well as, the highest tear index of the treated papers was in the treated sample with the thyme extracted at 60 amplitudes, 3 minutes, and 15% consumption amount based on the dry weight of the paper. The results of the optical tests showed that the opacity of the papers decreased and the brightness increased.Conclusion: The results of this research showed that the paper as a biodegradable and environmentally friendly material has the ability to be treated with herbal and natural antibacterial materials such as the thyme extract. Also, the herbal extracts are a suitable alternative to inorganic and metallic materials in the production of materials with antibacterial properties due to the herbal extracts are cheap, available and natural materials.
Nano composite
Bardia Sodeifi; Seyed Hassan Sharifi; Noredin Nazarnezhad
Abstract
Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added ...
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Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added to the poly caprolactone composite solution with amounts of (3%, 6%, and 9%), and their structural, mechanical, and barrier properties were investigated. According to the results of the field emission scanning electron microscopy (FESEM) test, the obtained nanoparticles are rod-shaped and have a length in the range of 100 to 150 nm and a diameter of 10 to 50 nm. X-ray diffraction (XRD) confirmed the formation of cellulose nanocrystals. According to the results, by adding cellulose nanocrystals to the composite solution, tensile strength, resistance to water solubility, and impermeability to the water vapor of the films increased, and only the elongation at break reduced. The best mechanical and barrier properties of the nanocomposites were obtained in the presence of 6% cellulose nanocrystals.
Noraldin Nazarnezhad; mahin avrand; Hosin Resalati
Abstract
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides ...
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One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides that can be used as a biodegradable coating in packaging papers. In this study, the effect of chitosan on the strength and barrier properties of coated liner paper was investigated. Chitosan was used in three levels 10, 15, and 20 g/L acetic acids (1%) and with two softener ratios (glycerol) of 0.5 and 1 (based on dry weight of chitosan) for papers coating. Strength properties including tensile, burst and tear index and barrier properties including water absorption, air resistance, and oil absorption in the coated samples were investigated. The Statistical analysis of results showed that the barrier properties increased significantly. Also, the effect of increasing the concentration of softener in the coating solution on the properties of air resistance and oil absorption was positive but negative for water absorption. The basis weight, burst and tear index of the coated samples increased with increasing coating weight, on the other hand the tensile strength decreased. Moreover, increasing the concentration of softener in the coating solution showed a negative effect on the properties of the samples. The results of the scanning electron microscope images showed that formation of chitosan film and the increase in the uniformity of the liner paper surfaces, especially in higher consumption amounts.
Negin Ghahrani; Noradin Nazarnezhad; Omid Ramezani; Ghasem Asadpour
Abstract
Regeneration of cellulose by direct solvent dissolution essentially involves the pretreatment of cellulose with a solvent for swelling the cellulose chains and weakening the cellulose molecules bonds. Aqueous solutions based on sodium hydroxide (NaOH) are low cost, non-volatile, non-toxic, environmentally ...
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Regeneration of cellulose by direct solvent dissolution essentially involves the pretreatment of cellulose with a solvent for swelling the cellulose chains and weakening the cellulose molecules bonds. Aqueous solutions based on sodium hydroxide (NaOH) are low cost, non-volatile, non-toxic, environmentally friendly cellulosic solvent with fast dissolution power at low temperatures. The mechanism of cellulose dissolution in this solvent is not yet fully understood because there are parameters such as temperature, crystallization and degree of cellulose polymerization that affect the solubility of cellulose in the NaOH / urea system. Therefore, this study investigated the effect of kappa factor changes in chlorine dioxide bleaching on the dissolution of OCC recycled pulp on chemical compounds (lignin and hemicellulose) and the degree of polymerization. The results showed that with further reduction of lignin, the dissolution of pulp decreases and this reduction in dissolution is more severe in lignin levels below 3% (reduction from 44% to about 37% dissolution). It seems that during the bleaching process and part of lignin and hemicellulose removal, a part of cellulose with low degree of polymerization is also removed and the average polymerization of the remaining cellulose increases which is more resistant to the phenomenon of pulp dissolution. With increasing kappa factor (to 0.2 and 0.3), there was no significant change in dissolution and hemicellulose. In general, it seems that lignin and the degree of polymerization are not only the effective factors in OCC pulp dissolving and hemicellulose content also can be effective.
Negin Ghahrani; Noraldin Nazrneghad; Omid Ramezani; Ghasem Asadpour
Abstract
One of the common applications of cellulose is dissolving pulp producing that requires high purity. Different cellulose sources are used to produce dissolving pulp. Due to Deforestation and lack of agricultural land and problems with cultivation, the use of wood and non-wood sources of cellulose is declining. ...
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One of the common applications of cellulose is dissolving pulp producing that requires high purity. Different cellulose sources are used to produce dissolving pulp. Due to Deforestation and lack of agricultural land and problems with cultivation, the use of wood and non-wood sources of cellulose is declining. Another source of cellulose is recycled pulp. Chlorine dioxide acts as a completely selective bleaching. Increasing kappa factors is very effective in removing lignin levels. In this research, dissolving pulp from recycled fibers is obtained during soda cooking and bleaching with chlorine dioxide. Then, the effect of changes in kappa factor of the second stage of chlorination on chemical composition (holocellulose and lignin), structural properties (degree of polymerization, alpha-cellulose and degree of brightness) and accessibility (water retention value) are investigated. The results showed that the degradation of holocellulose levels was not severe and did not cause cellulose damage and decreased alpha-cellulose levels as well as the degree of polymerization. The removal of lignin as a hydrophobic component and the presence of hemicellulose as a hydrophilic component increase accessibility (water retention) and decrease brightness degree.
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.
shaghayegh rezanezhad; Hossein Resalati; Seyed Majid Zabihzadeh
Abstract
The most important challenges of using minerals and fillers in the papermaking process are low retention and sharp reduced paper strength properties. In this research, magnetic papers were synthesized using commercial kraft fibers and iron salts. Nano-iron oxide has the same performance as fillers, as ...
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The most important challenges of using minerals and fillers in the papermaking process are low retention and sharp reduced paper strength properties. In this research, magnetic papers were synthesized using commercial kraft fibers and iron salts. Nano-iron oxide has the same performance as fillers, as a result, to prevent reducing strengths properties and retention of material in the final paper, chitosan uses as a strength agent and retention aid at 0, 10 and 15% levels. Characteristics of magnetic papers were investigated by atomic force microscope, scanning electron microscope, X-ray diffraction and vibration sample magnetometer. Tensile index and tear index were also determined in magnetic paper samples. The results of the microscopic examination showed that the magnetite nanoparticles were in the size range of 1 to 84 nm and the magnetic materials completely covered the fibers surface. Also, increasing chitosan content, increased the degree of loading and magnetic saturation of the samples. The magnetic paper samples had super para magnetic behavior. The results showed that adding chitosan at 10% increased tear and tensile strength but 15% chitosan decreased the strengths properties of magnetic paper.
Pulp and paper
Bardia Sodeifi; noureddin Nazarnezhad; Seyed Hassan Sharifi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific condition (PCL 10%, NCC 4 and 6%, ZnO 3%) were coated on the papers. The coating materials weight on the papers was (2.2- 2.7 g/m2). The results showed that the mechanical properties (Tensile strength index, Burst strength index and Tear strength index) of the coated papers were enhanced with addition of NCC. The ternary blend of these coating materials had the best mechanical properties than the neat paper. With addition of NCC the brightness were enhanced and the opacity were reduced. Also, the color properties were improved with addition of NCC and ZnO and the effect of ZnO was more remarkable than NCC but, in ternary blend of materials, the color properties were improved with increasing the amount of NCC.
Pulp and paper
Seyed Hassan Sharifi; nouredin Nazarnezhad
Abstract
To reuse recycled cellulosic fibers in paper production, contaminated particles and other impurities of the fibers can be greatly removed using a de-inking stage which is considered as a supplementary step in waste paper recycling technology. The effect of using ultrasonic pretreatment on the deinking ...
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To reuse recycled cellulosic fibers in paper production, contaminated particles and other impurities of the fibers can be greatly removed using a de-inking stage which is considered as a supplementary step in waste paper recycling technology. The effect of using ultrasonic pretreatment on the deinking of old newspapers was investigated utilizing the common conventional chemical method across this research work. Experimental design method was served to optimize the amount of ultrasonic bath temperature and sonication time. Therefore, 13 tests were designed using Response Surface Methodology (RSM) and Central Composite Design with Design Expert 7.0.0 Trial software. Ultrasonic bath temperature and sonication time at three different levels (1, 0 and 1+) and two axial points (α + and α-) were used as independent variables, and the optical and mechanical properties of handsheets were used as dependent variables. Response surfaces and contour plots were served to show the interaction between the independent variables and the response variable. ANOVA test showed that the quadratic model is the best model to explain the interaction among the studied variables. The predicted values of the obtained model had much conformity with the experimental results (R2=0.98). According to ANOVA results, it can be concluded that the effect of each of the variables on the optimal properties is significant and the ultrasonic time is the most effective factor on the response. According to the results, the proposed optimum conditions to achieve the highest amount of mechanical and optical properties (43.43) are the ultrasonic bath temperature 47 oC and the ultrasonic time of 31 min.
Composite wood products
Saeb Shabanpour; Noraldin Nazarnezhad; Maryam Ghorbani
Abstract
Current research was conducted to investigate the effect of nano Alumina modification on the mechanical and Surface properties of High-Density Fiberboard (HDF) made from oxidized fibers. Surface activation of fiber was done with 40% nitric acid. After fibers gluing with urea-formaldehyde (7% and 9% based ...
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Current research was conducted to investigate the effect of nano Alumina modification on the mechanical and Surface properties of High-Density Fiberboard (HDF) made from oxidized fibers. Surface activation of fiber was done with 40% nitric acid. After fibers gluing with urea-formaldehyde (7% and 9% based on the dry weight of fibers), the boards were made by hot pressing. For veneering, two types of paper with grammage of 70 and 80 g/m2 impregnated with melamine-formaldehyde and nano-alumina 0, 1.5 and 3% were applied. According to the results, the highest bending strength, modulus of elasticity and hardness were measured in nitric acid-modified fibers/ 9% glue/ grammage of 80 g/m2/3% nano-alumina samples that was significant increase compared to the control boards a significant increase. The samples weight loss due to abrasion was decreased with increasing the veneers grammage and nano-alumina, which confirmed the positive effect of nano-alumina. Veneer grammage did not show significant effect on the resistance to cigarette burn, but the highest concentration of nano-alumina resulted to improve this surface resistance via increase of thermal conductivity.
Pulp and paper
Mina Akbari; Ghasem asadpour; noorodin nazarnezhad
Abstract
As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment ...
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As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment process in Mazandaran wood and paper mill) on strength properties of fluting paper produced from both old corrugated container (OCC) and neutral sulfite semi chemical(NSSC) pulps. Calcium carbonate added to the pulps at levels of 5, 10 and 15 percentage of bone dry weight of paper. The air resistant with the tensile index, burst index, tear index and resistant to fluting of handsheets were measured and compared to control handsheets (samples without calcium carbonate). The results showed that the use of calcium carbonate from the water treatment has a negative impact on fluting paper strength properties. Calcium carbonate filler negative impacts on virgin pulp (NSSC) and recycled pulp (OCC) is different and is more in OCC pulp.
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.
Pulp and paper
fatemeh asadi; Noradin Nazarneghad; Ghasem Asadpoor atoeei
Abstract
Nowdays, algae considering marine ecosystem are regarded as producers and the first continuum that receives solar energy. Hence, they ensure the needed energy for the aquatic organism living. In global herbal division, algae have 1800 genus and 21000 types. Because of their presence in air rather than ...
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Nowdays, algae considering marine ecosystem are regarded as producers and the first continuum that receives solar energy. Hence, they ensure the needed energy for the aquatic organism living. In global herbal division, algae have 1800 genus and 21000 types. Because of their presence in air rather than underground water, algae allocate larger arena to themselves in comparise to other herbage. Based on accomplished studies, it is rated that algae have more than 7000 types in terms of biological diversity. Algae are used a lot. They are consumed in food industry, dung preparation, medicinal consumption and etc. In this study the green algae nanocellulose was used to improve CMP resistance.For the preparation of pure cellulose, algae samples initially affected the soda process and then were affected by bleaching sequence.. Next, the obtained cellulose has been converted to Nano-cellulose by using ultrasonic method. Nano-cellulose from cladophora algae was mixed with CMP in the ratios of 2, 5 and 8 percent. Finally, handmade paper was made and its resistive (strengh) properties were studied and compared with the pure hardwood CMP pulp. The results revealed that 8% treatment group had the highest density, tensile strength, burst strength, and control group had the lowest amount. Furthermore, the highest tear strength was related to control group; while, the lowest tear strength was for 8% treatment group.
Pulp and paper
Noraldin Nazarnezhad; Naser Rasol pour hedayati; Omid Ramazani
Abstract
Chitosan is known as a natural polymer which improves strengths of papers. So, in this study investigated improvement of chitosan absorption on modified craft fibers and increase its efficiency. The effects of chitosan were experimented in three levels of 0%, 0.75% and 1.25% on modified kraft fibers ...
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Chitosan is known as a natural polymer which improves strengths of papers. So, in this study investigated improvement of chitosan absorption on modified craft fibers and increase its efficiency. The effects of chitosan were experimented in three levels of 0%, 0.75% and 1.25% on modified kraft fibers surfaces with 3% hydrogen peroxide in different pH levels (5.5, 7 and 8.5). The results showed that chitosan had better performance at low dosages and alkaline conditions. Also surface fibers modification by hydrogen peroxide caused increase of carboxyl groups and fibers anionic charge. Fibers anionic charge with participant of chitosan formed a dual system. The apparent density increased from acidic pH to alkaline. As, the highest apparent density were reached in alkaline pH and 0.75 % of chitosan. Also, tensile index and burst index of paper were reached in alkaline pH and 0.75 % of chitosan. Whereas, chitosan and the surface modified fibers of kraft pulp did not have a significant level on the tear index
Physics and Mechanical Wood
parisa azari; mohammad talaeipour; noorodin nazarnezhad; behzad bazyar
Abstract
In this study the effect of surface oxidation of wood particles in order to reducing amount of adhesive for making single layer particleboard was investigated. Oxidation of wood particles cause to form carboxylic groups and free phenolic radicals that lead to activate the surface of wood particles for ...
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In this study the effect of surface oxidation of wood particles in order to reducing amount of adhesive for making single layer particleboard was investigated. Oxidation of wood particles cause to form carboxylic groups and free phenolic radicals that lead to activate the surface of wood particles for adhesion. This search was conducted on Populus nigra wood particles that they were oxidized by nitric acid (40%) including 0, 2, 4 and 6 percent (based on OD weight of wood). These wood particles were adhered by phenol formaldehyde resin in three amounts of 3, 5 and 7 percent (based on OD weight of wood) then wood particle cakes pressed in 180 degree of centigrade, 5 min and 30 kg/cm2. The results indicate that maximum MOR, MOE and minimum water absorption and swelling thickness was observed in boards with 7% adhesive and 4% acid. Using 5% adhesive and 4% acid had the best performance on shearing strength.
Salehe Nazari; Noraldin Nazarnezhad; Mohammad Ali Ebrahimzadeh
Abstract
Plants are a rich source of phenolic compounds as natural antioxidants. Antioxidants are the main factors in neutralizing free radicals and prevent the spread of diseases and destruction of many foods. These compounds are extractable from the bark of Eucalyptus camaldulensis and Pinus sylvestris trees. ...
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Plants are a rich source of phenolic compounds as natural antioxidants. Antioxidants are the main factors in neutralizing free radicals and prevent the spread of diseases and destruction of many foods. These compounds are extractable from the bark of Eucalyptus camaldulensis and Pinus sylvestris trees. The purpose of this study was to evaluate the antioxidant properties and total phenolic and flavonoids of Eucalyptus and pine wood bark. After preparation of the bark, ethanol extracts were extracted using soxhlet extractor. First the amount of total phenol and flavonoids of the extract was measured. Then to evaluate antioxidant properties of the extracts, four methods include Diphenyl Picryl Hydrazyl, reducing power; nitric oxide and metal chelating activity were used. The results showed that total phenol and flavonoid content, in eucalyptus bark was higher than pine. Test results to trap free radicals of diphenyl Pykryl Hydrazyl showed that 50% inhibitory concentration of ethanol extract of the Eucalypt and Pine bark values as 3.02 and 15.77 micrograms per milliliter, respectively. Also, in reducing power test, absorption rate for eucalyptus bark extract was higher than the pine. In nitric oxide trap test, 50% inhibitory concentration in ethanol extract of eucalypt bark was measured as 2.41 and in pine extract was 22.75 micrograms per milliliter. Furthermore, the results of Fe2+ chelating ability of ethanol extract of eucalyptus and pine bark at a concentration of 100 micrograms per milliliter inhibited 37 and 97/18 percent respectively. Ethanol extracts of the eucalypt and pine bark in four case study tests, showed an acceptable antioxidant activity. Thus, these compounds can be regarded as good sources ofnatural antioxidants.
