Chemistry of wood
Ramin Vaysi
Abstract
Background and aim: As a result of population growth, paper and wood products consumption has increased, and restrictions on using forest wood raw materials initiated the utilization poplar trees as fast-growing spices. The aim of this study was to focus on identification and comparison of the ...
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Background and aim: As a result of population growth, paper and wood products consumption has increased, and restrictions on using forest wood raw materials initiated the utilization poplar trees as fast-growing spices. The aim of this study was to focus on identification and comparison of the phenolic chemical components in poplar woods (Populus nigra and Populus deltoides).
Materials and methods: In this study, three trees from each poplar tree were randomly felled in plantation near Nowshar, Iran. Then three discs were cut from each log. At first, wood was grounded and then wood flour extractive were measured using TAPPI standard procedure. Wood flour was extracted by acetone and extractives residue was added to BSTFA reactor and samples were kept in constant temperature bath at 70oC for an hour. The extractive samples were then analyzed by GC/MS. The compounds were identified using GC diagram which shows abundance and retention time of each compound, and calculation of quartz index and Adams table.
Results: The result of GC-MS showed that there exist 68 and 105 compounds in wood of Populus nigra and Populus detoides, respectively. di-Limonene (30.26%), bis (2-ethylhexyl) phthalate (10.07%), Gamma-Sitosterol (1.06%), Hexadecanoic acid (2.0%), gamma-Terpinene (4.02%) and 4-Hydroxy-Benzoic acid (3.62%) were the most important compounds in wood of Populus detoides. There were the Limonene (25.62%), Anymol (5.29%), gamma-Terpinene (3.38%), 1, 2-Benzandicarboxylic acid (2.00%) and bis (2-ethylhexyl) phthalate (0.68%) as the most important compounds in wood of Populus nigra.
Conclusion: The gas chromatographs showed that Limonene, Benzene methanol, alpha-Terpineol, beta-Bisabolene, Hexadecanoic acid and bis (2-ethylhexyl) phthalate were the 7 common compounds in the wood of Populus nigra and Populus deltoides. These compounds can play an important role in the durability and consumption of these woods.
Management and Economics wood
Asghar Taremian; Mahdi Shahverdi; Saeid Eshaghi; Hadi Dashti
Abstract
In this study, the susceptibility of poplar (P. nigra) tension and normal wood to collapse during drying was investigated. Thus, the poplar boards with nominal dimensions of 100 × 50 × 25 mm (L×T×R) were dried using three different drying schedules. In schedule A, the boards were ...
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In this study, the susceptibility of poplar (P. nigra) tension and normal wood to collapse during drying was investigated. Thus, the poplar boards with nominal dimensions of 100 × 50 × 25 mm (L×T×R) were dried using three different drying schedules. In schedule A, the boards were dried under constant conditions (dry-bulb temperature of 600C and wet-bulb temperature of 440C); in schedules B and C, they were dried under a time-based schedule, consisting of 4 and 2 steps, respectively. The initial dry-bulb temperature in schedules A, B and C were selected as 60, 60 and 820C, respectively. After drying, the severity of collapse in the cross section of boards was determined by scanning electron microscope (SEM). The results revealed that collapse did not occur in the boards dried by schedule A. Collapse occurred slightly in the boards dried by schedule B and severe collapse and cell wall degradation developed in the boards dried by schedule C. In the latter, gelatinous layer of tension wood was separated from fiber cell walls. Tension wood was more sensitive to collapse than normal wood. Based on the results, it can be concluded that the occurrence of collapse is influenced by initial dry-bulb temperature rather than wet-bulb depression.
Management and Economics wood
Sohrab Rahimi; Mohammad mehdi Faezipoor; Saeid Eshaghi; Asghar Taremian
Abstract
Poplar lumbers with nominal thickness of 5 cm from Taleghan region, located in west of Karaj were dried under three different schedules including T8-F4 (recommended schedule by F.P.L for poplar), T8-F5 and T9-F4. The purpose of this research was to study the effects of the kiln’s rows (upper, middle, ...
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Poplar lumbers with nominal thickness of 5 cm from Taleghan region, located in west of Karaj were dried under three different schedules including T8-F4 (recommended schedule by F.P.L for poplar), T8-F5 and T9-F4. The purpose of this research was to study the effects of the kiln’s rows (upper, middle, lower) on the quality of the dried boards. Dry bulb temperatures for the schedules were adjusted at 54, 54 and 60 °C, while the final temperatures were adjusted at 82, 82 and 71 °C, respectively. The severity of warping, internal checking and surface checking in kiln dried lumbers were measured and analyzed. The results indicated that the boards in upper, middle and lower rows of the kiln, in all three schedules, did not have any significant difference in 95% confidence interval. Also, the final moisture content of the boards in all three rows and all three schedules were in acceptable quality.
