Chemistry of wood
Maryam Ahmadi; Seyed Majid Zabihzadeh; Noureddin Nazarnezhad; Ghasem Asadpour; Pourya Biparva
Abstract
Background and objectives: Plant extracts contain antioxidant compounds, which have garnered increasing attention in various scientific and industrial fields due to their significance. Among the most important groups of compounds present in plant extracts are phenolic compounds. These compounds not only ...
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Background and objectives: Plant extracts contain antioxidant compounds, which have garnered increasing attention in various scientific and industrial fields due to their significance. Among the most important groups of compounds present in plant extracts are phenolic compounds. These compounds not only possess antioxidant properties but also have diverse applications in various industries. Numerous plants have been investigated for the extraction of bioactive compounds. Chinaberry (Melia azedarach), a woody species, is known to contain antioxidant substances. In this study, the extracts from heartwood and sapwood of chinaberry were obtained, and the extracted compounds were identified. Additionally, the antioxidant properties of these compounds were evaluated. This research provides valuable insights into the potential applications of antioxidant compounds derived from chinaberry in different industries.Methodology: First, the heartwood and sapwood of Melia azedarach (chinaberry) were separated and ground using a laboratory mill. Particles of size 60 mesh were isolated using a laboratory sieve. Prior to extraction, the wood flour underwent pre-extraction with hexane. Three different extraction methods were employed: Soxhlet, immersion, and ultrasonic. In all methods, 10 grams of wood flour were used as the raw material. In the Soxhlet method, the raw material was placed in a thimble and then the thimble contain wood flour transferred to a flask containing 250 mL of ethanol. The Soxhlet system was set up, and after the first siphoning, the samples were heated for 6 hours to complete the extraction process. In the immersion method, the samples were stirred with 250 mL of ethanol at 40°C for 24 hours using a magnetic stirrer. In the ultrasonic method, the wood flour was combined with 100 mL of ethanol in a beaker. The resulting mixture was treated at 40°C for a total of 6 minutes, divided into two 3-minute intervals, using ultrasonic waves at a frequency of 20 kHz and an amplitude of 50%. The compounds present in the extracts obtained from all three methods were identified using GC-MS analysis. The total phenolic and flavonoid content of the extracts was quantified. Additionally, the antioxidant activity of the extracts was evaluated using the DPPH method.Results: The analysis of extractable content before pre-extraction with hexane revealed that the heartwood contained a higher number of extractable materials compared to the sapwood. Following extraction using three different methods, a re-assessment of extractable content indicated that the highest amount was obtained from the sapwood using the Soxhlet method. GC-MS analysis of extracts derived from the heartwood and sapwood of Melia azedarach showed that methoxyphenol was the predominant phenolic compound identified in both wood types when extracted using the Soxhlet method. In the immersion method, beta-sitosterol was the most abundant compound in the heartwood, while methylphenol dominated in the sapwood. For the ultrasonic method, imidazolidinedione was the most abundant compound in the heartwood, and beta-sitosterol prevailed in the sapwood. The highest phenolic compound content was observed in the sapwood extract obtained using the Soxhlet method, measuring 0.45865 µg gallic acid per mg of extract. The maximum flavonoid content was also recorded in the sapwood extract from the Soxhlet method, with 0.493172 mg quercetin per gram of dry weight. Antioxidant activity assessment demonstrated that the extract obtained from the heartwood using the immersion method exhibited the highest antioxidant activity.Conclusion: This study aimed to investigate the extraction of heartwood and sapwood from Melia azedarach and evaluate the impact of three different extraction methods- soxhlet, immersion, and ultrasonic- on the yield of the extracted materials. Additionally, the antioxidant properties of the extracts obtained through these methods were assessed. The results revealed that phenolic compounds constituted the majority of the extracted materials in both heartwood and sapwood extracts of this species. The soxhlet method demonstrated the highest efficiency in extracting phenolic and flavonoid compounds from the sapwood, while the immersion method exhibited the highest antioxidant activity in the extracts obtained from the heartwood. These findings underscore the influence of the extraction method on the quantity and type of compounds extracted as well as their antioxidant properties. This study provides valuable insights into the potential utilization of antioxidant compounds in industrial and pharmaceutical applications.
Management and Economics wood
Elham Hatamzadeh Arabi; Maryam Ghorbani; Prya Biparva
Abstract
The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc ...
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The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc oxide nanoparticles, nanocomposite and nano/Styrene. Mechanical and biological tests samples according toASTM-D143 and EN113 respectively were treated by vacuum- pressure method using cylinder experimental. The mechanical tests were considered for each level 5 repeat and for biological test for each level 10 repeat. The presence of zinc oxide nanoparticles on cell wall and styrene in the cell cavities were confirmed by Scanning electron microscopy. According to the results, bending strength, bending modulus, hardness and pressure parallel to grain for nano/styrene samples with highest improvement were increased 36.74, 40.23, 60.58 and 25.07 in comparison with control respectively. Also, decay resistance of treated samples increased, so that maximum and least weight loss were recorded for control and nano/styrene samples with 25.81 and 3.37% weight loss.
Management and Economics wood
Neda Esmaeili; Maryam Ghorbani; Porya Biparva
Abstract
In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently ...
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In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently with paraffin by vacuum-pressure method. Increasing concentration of glutaraldehyde caused to weight gain and bulking wood cell wall, subsequently reduced paraffin penetration into the porous structure of wood. Biological resistance exposed to white rot fungi and mechanical properties were measured according to the standards EN113 and ASTM D143-94, respectively. Scanning electron microscopic images showed bulking of cell walls and paraffin presence in cell cavities. According to results of TGA, increasing of modification intensity decreased mass loss due to cross linking formation between glutaraldehyde and cell wall polymers. Paraffin at combined modification containing 10% and 20% glutaraldehyde improved significantly the modulus of elasticity. Glutaraldehyde reduced bending strength, but paraffin present in the modified samples improved it. The Glutaraldehyde increased compression strength parallel to grain and hardness that the improvement was more obvious in combined modification. Modification with glutaraldehyde enhanced decay resistance exposed to white rot fungi, and this improvement intensified at the presence of paraffin. Inhibitory influence of chemical modification on wood attacking white rot fungi can be attributed to decreases the wood moisture, bulking of cell walls and blocking cell cavities.
Management and Economics wood
Elham Hatamzadeh; Maryam Ghorbani; Poria bi parva
Abstract
In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according ...
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In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according to ASTM-D4446-05, and divided to three levels; control, Zncl2/NH3 and Zncl2/Naoh at 0.05M concentration and pH=10. Test samples were impregnated with salty precursor in the experimental cylinder using vacuum-pressure method, and in order to adjust the pH, soda and ammonia added. Due to the electron microscope images, change the type of precursor deposition, caused the different structure of ZnO nanoparticle. Retention of zinc oxide nanoparticles, density changes, water absorption, swelling and anti-swelling efficiency (ASE) were determined after synthesis. Retention of zinc chloride precursor with ammonia and soda acidity regulator was determined 4.43 and 1.71kg/m3 respectively. Water absorption increased at first hours of immersion, and then decreased. These treatments increased water absorption of wood. Least swelling and water absorption, and maximum ASE were measured in Zncl2/NH3 level.
