In this paper, the heat tratment of wood samples of 8 tree species with different colour were made at different temperature and time. Using SC-1 Model colorimeter, the colorimetric parameter was measured at quantitati...In this paper, the heat tratment of wood samples of 8 tree species with different colour were made at different temperature and time. Using SC-1 Model colorimeter, the colorimetric parameter was measured at quantitative measuring for treatment fore-and-after wood sampIes color. The effect of heat treatment conditions on wood color was analyzed. The results indicated: the temperature and time of heat treatment affected on big extent for wood samples color, in which the heat temperature was more evident than others. The luminance index of wood color parameter was more sensitive to treatment condition, which it reduced with temperature and time increasing, this kind of variation tendency was the same as all wood samples, but the variations extent was more different among the different wood species. After heat treatment the wood color hue and saturation variation direction were different for different wood species.This phenomenon had the relation to the migration and volatilization of color extract in heating process, or the rapid oxidation of lignin and some chemical element in high temperature.展开更多
Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors ...Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.展开更多
In order to improve the dimensional stability of wood-polymer composites, wood flour pre-treated by polyethylene glycol （PEG） at two different concentrations and then thermally treated at 140℃, was used as raw mate...In order to improve the dimensional stability of wood-polymer composites, wood flour pre-treated by polyethylene glycol （PEG） at two different concentrations and then thermally treated at 140℃, was used as raw material to produce wood flour/poly- propylene （PP） composites at a wood content of 40%. The structure of modified wood flour was analyzed with a scanning electron microscope （SEM） and its effect on the physical and mechanical properties of wood flour/PP composites was evaluated. The SEM results indicated the ＂bulking＂ effect of PEG on wood flour, which resulted in reduced water uptake. The combination of PEG and heat treatment further improved the moisture resistance of the composites. However, PEG modification had a negative effect on the flexural modulus of rupture （MOR） and the modulus of elasticity （MOE）; whereas heat treatment partly compensated for this reduc- tion. For dynamic mechanical properties, PEG treatment decreased the storage modulus （E＇）. However, the heat treatment resulted in an increase orE＇ of the wood flour/PP composites, with the temperature of loss factor peaks shifting to a higher temperature.展开更多
文摘In this paper, the heat tratment of wood samples of 8 tree species with different colour were made at different temperature and time. Using SC-1 Model colorimeter, the colorimetric parameter was measured at quantitative measuring for treatment fore-and-after wood sampIes color. The effect of heat treatment conditions on wood color was analyzed. The results indicated: the temperature and time of heat treatment affected on big extent for wood samples color, in which the heat temperature was more evident than others. The luminance index of wood color parameter was more sensitive to treatment condition, which it reduced with temperature and time increasing, this kind of variation tendency was the same as all wood samples, but the variations extent was more different among the different wood species. After heat treatment the wood color hue and saturation variation direction were different for different wood species.This phenomenon had the relation to the migration and volatilization of color extract in heating process, or the rapid oxidation of lignin and some chemical element in high temperature.
基金Provincial Science and Technology Research Project of Guangdong(2014A040401043)
文摘Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.
基金supported by the National Natural Science Foundation of China (Grant No.30871966)
文摘In order to improve the dimensional stability of wood-polymer composites, wood flour pre-treated by polyethylene glycol （PEG） at two different concentrations and then thermally treated at 140℃, was used as raw material to produce wood flour/poly- propylene （PP） composites at a wood content of 40%. The structure of modified wood flour was analyzed with a scanning electron microscope （SEM） and its effect on the physical and mechanical properties of wood flour/PP composites was evaluated. The SEM results indicated the ＂bulking＂ effect of PEG on wood flour, which resulted in reduced water uptake. The combination of PEG and heat treatment further improved the moisture resistance of the composites. However, PEG modification had a negative effect on the flexural modulus of rupture （MOR） and the modulus of elasticity （MOE）; whereas heat treatment partly compensated for this reduc- tion. For dynamic mechanical properties, PEG treatment decreased the storage modulus （E＇）. However, the heat treatment resulted in an increase orE＇ of the wood flour/PP composites, with the temperature of loss factor peaks shifting to a higher temperature.
