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Artificial Weathering
The Experts below are selected from a list of 2475 Experts worldwide ranked by ideXlab platform
Quanlin Zhao – 1st expert on this subject based on the ideXlab platform
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correlation between uv condensation and xe Artificial Weathering tests on ethylene propylene diene monomer rubber
Journal of Failure Analysis and Prevention, 2011Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Artificial Weathering tests on ethylene–propylene–diene monomer (EPDM) rubber were conducted in a fluorescent UV/condensation Weathering equipment (E-UV environment) and a xenon lamp light exposure and Weathering equipment (E-Xe environment) for different time periods. The correlation between E-UV and E-Xe environment was investigated by using crosslink density as criteria. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of EPDM. The fracture morphology was monitored by scanning electron microscope (SEM). The results showed that the correlation between E-UV and E-Xe environments can be expressed as: \( t_{\text{Xe}} = – 7.4818 + 1.1837t_{{{\text{Xe}}{-}{\text{UV}}}} , \) where the correlation coefficient R is 0.9856. The thermal stability of EPDM did not deteriorate dramatically on exposure to the two Artificial Weathering environments. An oxidation layer was formed after 90 days of exposure.
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Correlation Between UV/Condensation and Xe Artificial Weathering Tests on Ethylene–Propylene–Diene Monomer Rubber
Journal of Failure Analysis and Prevention, 2011Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Artificial Weathering tests on ethylene–propylene–diene monomer (EPDM) rubber were conducted in a fluorescent UV/condensation Weathering equipment (E-UV environment) and a xenon lamp light exposure and Weathering equipment (E-Xe environment) for different time periods. The correlation between E-UV and E-Xe environment was investigated by using crosslink density as criteria. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of EPDM. The fracture morphology was monitored by scanning electron microscope (SEM). The results showed that the correlation between E-UV and E-Xe environments can be expressed as: \( t_{\text{Xe}} = – 7.4818 + 1.1837t_{{{\text{Xe}}{-}{\text{UV}}}} , \) where the correlation coefficient R is 0.9856. The thermal stability of EPDM did not deteriorate dramatically on exposure to the two Artificial Weathering environments. An oxidation layer was formed after 90 days of exposure.
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surface degradation of unsaturated polyester resin in xe Artificial Weathering environment
Materials & Design, 2010Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Unsaturated polyester (UP) resin samples were exposed to Artificial Weathering environment produced by a xenon lamp light exposure and Weathering equipment for different time intervals. The change of appearance, optical property, chemical structure and surface microstructure before and after exposure in this environment was monitored by spectrophotometer, gloss meter, Specular Reflection Fourier Transform Infrared (SR-FTIR) spectroscopy and three-dimensional digital microscope. The results showed that the surface of UP resin turned darker and yellower in the whole Weathering stage. Gloss decreased with increasing aging time due to the increase of surface roughness. SR-FTIR results showed that ester bonds in polymeric chains broke in the aging process. With increasing aging time, small voids can be observed on UP surface and expanded gradually to cracks.
Xiaogang Li – 2nd expert on this subject based on the ideXlab platform
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correlation between uv condensation and xe Artificial Weathering tests on ethylene propylene diene monomer rubber
Journal of Failure Analysis and Prevention, 2011Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Artificial Weathering tests on ethylene–propylene–diene monomer (EPDM) rubber were conducted in a fluorescent UV/condensation Weathering equipment (E-UV environment) and a xenon lamp light exposure and Weathering equipment (E-Xe environment) for different time periods. The correlation between E-UV and E-Xe environment was investigated by using crosslink density as criteria. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of EPDM. The fracture morphology was monitored by scanning electron microscope (SEM). The results showed that the correlation between E-UV and E-Xe environments can be expressed as: \( t_{\text{Xe}} = – 7.4818 + 1.1837t_{{{\text{Xe}}{-}{\text{UV}}}} , \) where the correlation coefficient R is 0.9856. The thermal stability of EPDM did not deteriorate dramatically on exposure to the two Artificial Weathering environments. An oxidation layer was formed after 90 days of exposure.
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Correlation Between UV/Condensation and Xe Artificial Weathering Tests on Ethylene–Propylene–Diene Monomer Rubber
Journal of Failure Analysis and Prevention, 2011Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Artificial Weathering tests on ethylene–propylene–diene monomer (EPDM) rubber were conducted in a fluorescent UV/condensation Weathering equipment (E-UV environment) and a xenon lamp light exposure and Weathering equipment (E-Xe environment) for different time periods. The correlation between E-UV and E-Xe environment was investigated by using crosslink density as criteria. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of EPDM. The fracture morphology was monitored by scanning electron microscope (SEM). The results showed that the correlation between E-UV and E-Xe environments can be expressed as: \( t_{\text{Xe}} = – 7.4818 + 1.1837t_{{{\text{Xe}}{-}{\text{UV}}}} , \) where the correlation coefficient R is 0.9856. The thermal stability of EPDM did not deteriorate dramatically on exposure to the two Artificial Weathering environments. An oxidation layer was formed after 90 days of exposure.
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surface degradation of unsaturated polyester resin in xe Artificial Weathering environment
Materials & Design, 2010Co-Authors: Quanlin Zhao, Xiaogang Li, Zhengfang YeAbstract:Unsaturated polyester (UP) resin samples were exposed to Artificial Weathering environment produced by a xenon lamp light exposure and Weathering equipment for different time intervals. The change of appearance, optical property, chemical structure and surface microstructure before and after exposure in this environment was monitored by spectrophotometer, gloss meter, Specular Reflection Fourier Transform Infrared (SR-FTIR) spectroscopy and three-dimensional digital microscope. The results showed that the surface of UP resin turned darker and yellower in the whole Weathering stage. Gloss decreased with increasing aging time due to the increase of surface roughness. SR-FTIR results showed that ester bonds in polymeric chains broke in the aging process. With increasing aging time, small voids can be observed on UP surface and expanded gradually to cracks.
Xianai Huang – 3rd expert on this subject based on the ideXlab platform
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Comparison of Weathering behavior of heat-treated jack pine during different Artificial Weathering conditions
, 2020Co-Authors: Duygu Kocaefe, Xianai Huang, Yasar S KocaefeAbstract:Heat treatment improves the dimensional stability (reduced hygroscopicity and wettabilty) of wood and its resistance to fungi, and results in darker color. However, wood loses its color when exposed to Weathering (sunlight, rain etc.). In this study, the surface degradation and color loss of het-treated wood taking place during Weathering were investigated under different conditions. Jack pine (Pinus banksiana) samples, heat-treated at 210°C, were exposed to Artificial Weathering with and without water spray for different times. Before and after exposure, their color and wettability by water were determined. Structural changes and chemical modifications at exposed surfaces were also investigated using florescent microscopy, SEM, FTIR spectroscopy, and XPS. The results revealed that the photo-degradation of lignin play important roles in color change and wetting behavior of heat-treated wood surfaces during Weathering. Heat-treated wood was degraded more during Weathering if exposed to water spray.
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Study of the degradation of heat-treated jack pine under different Artificial Weathering conditions
, 2020Co-Authors: Duygu Kocaefe, Xianai Huang, Yasar S KocaefeAbstract:Heat-treated wood is a natural product heat-treated at high temperatures in the range of 180 to 240°C. Heat treatment modifies wood both chemically and physically. However, heat-treated wood is susceptible to Weathering degradation. It is of considerable importance to investigate the influence of Weathering on the degradation processes of heat-treated wood under different conditions. Jack pine (Pinus banksiana) heat-treated at different temperature were exposed to Artificial Weathering with and without water spray for different periods in order to understand the effect of Weathering factors on degradation processes. Before and after Weathering, their color and wettability by water were determined. Structural changes and chemical modifications at exposed surfaces were also investigated using florescent microscopy imaging, SEM, FTIR spectroscopy, and XPS. The results revealed that heat-treated wood was degraded more during Weathering with water spray than without water spray.
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quantitative characterization of chemical degradation of heat treated wood surfaces during Artificial Weathering using xps
Surface and Interface Analysis, 2013Co-Authors: Duygu Kocaefe, Xianai Huang, Yasar S Kocaefe, Yaman BolukAbstract:The X-ray photoelectron spectroscopy (XPS) study of three heat-treated North American wood species (jack pine, birch and aspen) was carried out to evaluate chemical modifications occurring on the wood surface during Artificial Weathering for different times. The results suggest that the Weathering reduces lignin content (aromatic rings) at the surface of heat-treated wood, consequently, the carbohydrates content increases. This results in surfaces richer in cellulose and poorer in lignin. Heat-treated wood surfaces become acidic due to Weathering, and the acidity increases as the Weathering time increases. Three possible reasons are given to account for the increase of acidity during Weathering. The lignin content increases, whereas the hemicelluloses content decrease due to heat treatment. Heat-treated woods have lower acidity to basicity ratios than the corresponding untreated woods for all three species because of the decrease in carboxylic acid functions mainly present in hemicelluloses. The wood composition changes induced by Weathering are more significant compared to those induced by heat treatment at wood surface. Exposure to higher temperatures causes more degradation of hemicelluloses, and this characteristic is maintained during Weathering. However, the wood direction has more effect on chemical composition modification during Weathering compared to that of heat treatment temperature. The heat-treated jack pine is affected most by Weathering followed by heat-treated aspen and birch. This is related to differences in content and structure of lignin of softwood and hardwood. The use of XPS technique has proved to be a reliable method for wood surface studies. Copyright © 2012 John Wiley & Sons, Ltd.