Wood Modification and Wood Preservation
َAmir Mohamad Nahofteh Estarabadi; Davood Rasouli; Taghi Tabarsa; Abolghasem Khazaeian
Abstract
Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. ...
Read More
Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year.Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings. Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood.Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year. .Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings.Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .
Davood Rasouli; Hossein Yousefi; Mahdi Mashkour
Abstract
In this research, the effect of using nano-zinc oxide (nano-ZnO) as a UV absorbent on the weathering resistance of wood- polypropylene composite was investigated. For this purpose, composite samples containing 0, 1, 2 and 3% nano-ZnO were manufactured using an internal mixer and a laboratory press. ...
Read More
In this research, the effect of using nano-zinc oxide (nano-ZnO) as a UV absorbent on the weathering resistance of wood- polypropylene composite was investigated. For this purpose, composite samples containing 0, 1, 2 and 3% nano-ZnO were manufactured using an internal mixer and a laboratory press. The prepared specimens were exposed to artificial weathering for 1480 hrs (in the periods of 0 ,480, 960 and 1480 hrs). The weathering degradation of specimens was monitored by tensile strength, hardness, colorimetry, Fourier transform infrared spectroscopy (FTIR), and, stereomicroscope tests. Results showed that weathering caused color changes, tensile strength and hardness loss, physical and chemical degradation on the surface of the samples. The use of nano-ZnO partially prevented tensile strength and hardness loss of samples as well as their surface degradation. In general, the use of 2% nano ZnO has been a better performance against weathering than other values.
Hossein Yousefi; Elyas Afra; Davood Rasouli; mahdi mashkour
Abstract
In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic ...
Read More
In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic surfaceones. The micrographs of FE-SEM confirmed the nano-scale size of cellulose nanofibers. XPS results showed that the surface of specimens contains silane. With the treatment of silane, the water droplet contact angle increased to 104 and 153 degree in nanopaper and 153 paper, respectivelydegree in paper. Because of this, the surface of treated paper can be regarded as super hydrophobic surface. TGA confirmed that the ash content of treated specimens were higher than those of untreated ones and also it was revealed that the silane treatment made a multi-layers coating on the surface of specimens. The treated specimens showed less water absorption and higher mechanical properties than untreated ones. The silane coupling treatment made water hydrophobic surfaces onof cellulose paper and nanopaper made them water-proof which can led to the development of their applications for outdoorshumid conditions.
Composite wood products
Ali akbar Enayati; Davood Rasooli; Hossein Usefi
Abstract
In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were ...
Read More
In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were used for control samples(120 and 40 g/m2 respectively). Physical and mechanical properties including MOR and MOE (parallel and perpendicular to grain of face layers), water absorption and thickness swelling after 2 and 24 hours of immersion in water were tested. The results showed that maleic anhydride polypropylene coupling agent has significant effect on MOR parallel to grain of face layers. With increase of maleic anhydride polypropylene coupling agent, MOR increased. Polypropylene has positive effect on thickness. With increase of maleic anhydride polypropylene coupling agent, water absorption after 24 hours improved. Although the results revealed improvement in board properties resulted from more polypropylene use but in all properties (except thickness swelling after 24 hours), control samples had better quality than plywood made from polypropylene.
