The Experts below are selected from a list of 3735 Experts worldwide ranked by ideXlab platform
Quanlin Zhao - One of the best experts 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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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.
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degradation characterization of ethylene propylene diene monomer epdm rubber in artificial weathering environment
Journal of Failure Analysis and Prevention, 2010Co-Authors: Quanlin Zhao, Jianwen Hu, Xiaogang Li, Zhengfang YeAbstract:Ethylene-propylene-diene monomer containing 5-ethylidene-2-norbornene as diene was exposed to artificial weathering environment produced by a Xenon Lamp light exposure and weathering equipment for different periods of time. The changes of surface color and mechanical properties were monitored by spectrophotometer, computer-controlled tensile testing and hardness measurements. Crosslink density of ethylene-propylene-diene monomer specimens was measured by the solvent swell method. The results showed that the surface of ethylene-propylene-diene monomer became yellower due to the form of carbonyl group. The degradation process proceeded predominantly via cross-linking. With increase in crosslink density, the tensile strength increased and the elongation at fracture decreased.
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ageing behavior of acrylic polyurethane varnish coating in artificial weathering environments
Progress in Organic Coatings, 2009Co-Authors: Quanlin Zhao, Jianwen Hu, Xiaogang LiAbstract:Acrylic polyurethane varnish coatings were exposed in two artificial weathering environments produced by a fluorescent UV/condensation weathering device and a Xenon Lamp exposure and weathering equipment for different time periods. The ageing behavior of the coating was evaluated by using film thickness gauge, glossmeter, spectrophotometer, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The results showed that the Xenotest protocol had a significant effect on the thickness loss and gloss. However, the yellow index measurements and low frequency impedance showed that greater degradation was caused by the UV exposure protocol. These findings were supported by the results obtained from FTIR analysis. In the two artificial weathering environments, the low frequency impedance modulus of intact coatings decreased exponentially with increase of ageing time, and correlated with the changes of other properties of ageing coatings, which can be used to predict coatings lifetime.
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degradation evaluation of ethylene propylene diene monomer epdm rubber in artificial weathering environment by principal component analysis
Materials Letters, 2009Co-Authors: Quanlin Zhao, Xiaogang LiAbstract:Abstract Artificial weathering tests on ethylene–propylene–diene monomer (EPDM) containing 5-ethylidene-2-norbornene (ENB) as diene were conducted in a Xenon Lamp light exposure and weathering equipment for different time periods. Principal component analysis (PCA) was used to evaluate the 12 degradation parameters of EPDM including surface properties, crosslink density and mechanical properties. The results showed that the combined evaluating parameter Z of EPDM degradation increased quickly in the first 12 days of exposure and then leveled off. After 45 days, it began to increase rapidly again. Among the 12 degradation parameters, the crosslink density is strongly associated with tensile stress at 300% elongation and tear strength. The surface tension is also well correlated with the color aberration.
Xiaogang Li - One of the best experts 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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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.
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degradation characterization of ethylene propylene diene monomer epdm rubber in artificial weathering environment
Journal of Failure Analysis and Prevention, 2010Co-Authors: Quanlin Zhao, Jianwen Hu, Xiaogang Li, Zhengfang YeAbstract:Ethylene-propylene-diene monomer containing 5-ethylidene-2-norbornene as diene was exposed to artificial weathering environment produced by a Xenon Lamp light exposure and weathering equipment for different periods of time. The changes of surface color and mechanical properties were monitored by spectrophotometer, computer-controlled tensile testing and hardness measurements. Crosslink density of ethylene-propylene-diene monomer specimens was measured by the solvent swell method. The results showed that the surface of ethylene-propylene-diene monomer became yellower due to the form of carbonyl group. The degradation process proceeded predominantly via cross-linking. With increase in crosslink density, the tensile strength increased and the elongation at fracture decreased.
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ageing behavior of acrylic polyurethane varnish coating in artificial weathering environments
Progress in Organic Coatings, 2009Co-Authors: Quanlin Zhao, Jianwen Hu, Xiaogang LiAbstract:Acrylic polyurethane varnish coatings were exposed in two artificial weathering environments produced by a fluorescent UV/condensation weathering device and a Xenon Lamp exposure and weathering equipment for different time periods. The ageing behavior of the coating was evaluated by using film thickness gauge, glossmeter, spectrophotometer, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The results showed that the Xenotest protocol had a significant effect on the thickness loss and gloss. However, the yellow index measurements and low frequency impedance showed that greater degradation was caused by the UV exposure protocol. These findings were supported by the results obtained from FTIR analysis. In the two artificial weathering environments, the low frequency impedance modulus of intact coatings decreased exponentially with increase of ageing time, and correlated with the changes of other properties of ageing coatings, which can be used to predict coatings lifetime.
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degradation evaluation of ethylene propylene diene monomer epdm rubber in artificial weathering environment by principal component analysis
Materials Letters, 2009Co-Authors: Quanlin Zhao, Xiaogang LiAbstract:Abstract Artificial weathering tests on ethylene–propylene–diene monomer (EPDM) containing 5-ethylidene-2-norbornene (ENB) as diene were conducted in a Xenon Lamp light exposure and weathering equipment for different time periods. Principal component analysis (PCA) was used to evaluate the 12 degradation parameters of EPDM including surface properties, crosslink density and mechanical properties. The results showed that the combined evaluating parameter Z of EPDM degradation increased quickly in the first 12 days of exposure and then leveled off. After 45 days, it began to increase rapidly again. Among the 12 degradation parameters, the crosslink density is strongly associated with tensile stress at 300% elongation and tear strength. The surface tension is also well correlated with the color aberration.
Carmelo Garcia Barroso - One of the best experts on this subject based on the ideXlab platform.
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changes in the polyphenolic and volatile content of fino sherry wine exposed to high temperature and ultraviolet and visible radiation
European Food Research and Technology, 2006Co-Authors: P Benitez, Remedios Castro, Ramon Natera, Carmelo Garcia BarrosoAbstract:Experiments of accelerated oxidation of “Fino” Sherry wines have been conducted at different temperatures (25 and 45 °C) and under the influence of UV–Vis radiation (a Xenon Lamp of 1500 W). Two types of glass bottle were employed: topaz bottles (with low values of transmittance in the UV–Vis range) and transparent bottles. To identify significant differences between the wine before and after being subjected to the influence of these factors, the values of absorbance at 420 nm and the concentrations of various polyphenolic and volatile compounds were submitted to a multivariate variance analysis. The three factors “temperature”, “radiation”, and “time” had a statistically significant effect on the values of absorbance at 420 nm and on the concentration of most of the polyphenolic and volatile compounds, while the “bottle” factor was only significant for polyphenol content. All the wines showed losses in several polyphenolic compounds, which were more severe for the wines bottled in transparent glass. The combined application of high temperature and UV–Vis radiation provoked significant decreases in most of the volatile compounds monitored.
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changes in the polyphenolic and volatile contents of fino sherry wine exposed to ultraviolet and visible radiation during storage
Journal of Agricultural and Food Chemistry, 2003Co-Authors: P Benitez, Remedios Castro, Carmelo Garcia BarrosoAbstract:: Experiments of accelerated oxidation of "fino" sherry wines have been conducted at 25 degrees C and under the influence of UV-visible radiation (a Xenon Lamp of 1500 W). With the aim of determining the contribution of UV-vis radiation to the browning phenomenon, two types of glass bottles were employed: topaz bottles (with low values of transmittance in the UV-visible range) and transparent bottles. To identify significant differences between the wine before and after being subjected to the influence of the UV-vis radiation, the values of absorbance at 420 nm and the concentrations of various polyphenolic and volatile compounds were submitted to a multivariate variance analysis. Both factors considered (time and type of bottle) had a statistically significant effect on the values of absorbance at 420 nm and on the concentration of most of the polyphenolic compounds, whereas only the "time" factor was significant for volatile compounds. All wines showed losses in several polyphenolic compounds, which were more severe for the wines bottled in transparent glasses. However, these wines exhibited a lower degree of visual browning (abs 420 nm). In the case of volatile compounds, most of these presented increases during storage exposed to the influence of the UV-vis radiation.
Zhengfang Ye - One of the best experts 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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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.
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degradation characterization of ethylene propylene diene monomer epdm rubber in artificial weathering environment
Journal of Failure Analysis and Prevention, 2010Co-Authors: Quanlin Zhao, Jianwen Hu, Xiaogang Li, Zhengfang YeAbstract:Ethylene-propylene-diene monomer containing 5-ethylidene-2-norbornene as diene was exposed to artificial weathering environment produced by a Xenon Lamp light exposure and weathering equipment for different periods of time. The changes of surface color and mechanical properties were monitored by spectrophotometer, computer-controlled tensile testing and hardness measurements. Crosslink density of ethylene-propylene-diene monomer specimens was measured by the solvent swell method. The results showed that the surface of ethylene-propylene-diene monomer became yellower due to the form of carbonyl group. The degradation process proceeded predominantly via cross-linking. With increase in crosslink density, the tensile strength increased and the elongation at fracture decreased.
Li Zhang - One of the best experts on this subject based on the ideXlab platform.
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structural evolution of chars from biomass components pyrolysis in a Xenon Lamp radiation reactor
Chinese Journal of Chemical Engineering, 2017Co-Authors: Shurong Wang, Li Zhang, Jinsong Zhou, Zhongyang LuoAbstract:Abstract The structural evolution of the chars from pyrolysis of biomass components (cellulose, hemicellulose and lignin) in a Xenon Lamp radiation reactor was investigated. The elemental composition analysis showed that the C content increased at the expense of H and O contents during the chars formation. The values of ΔH/C/ΔO/C for the formation of cellulose and hemicellulose chars were close to 2, indicating that dehydration was the dominant reaction. Meanwhile, the value was more than 3 for lignin char formation, suggesting that the occurrence of demethoxylation was prevalent. FTIR and XRD analyses further disclosed that the cellulose pyrolysis needed to break down the stable crystal structure prior to the severe depolymerization. As for hemicellulose and lignin pyrolysis, the weak branches and linkages decomposed firstly, followed by the major decomposition. After the devolatilization at the main pyrolysis stage, the three components encountered a slow carbonization process to form condensed aromatic chars. The SEM results showed that the three components underwent different devolatilization behaviors, which induced various surface morphologies of the chars.
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enhanced decolorization of orange ii solutions by the fe ii sulfite system under Xenon Lamp irradiation
Industrial & Engineering Chemistry Research, 2013Co-Authors: Mei Xiao, Long Che, Li ZhangAbstract:Decolorization of Orange II by a ferrous sulfite system in aqueous solutions under a Xenon Lamp (350W) was investigated to determine the enhancement of decolorization efficiency under UV–vis irradiation. Orange II (10 mg L–1) was efficiently decolorized at an initial pH of 6.1 under irradiation (84% efficiency at 60 min), whereas only 15% efficiency was achieved without irradiation. Although 4 was the optimum pH for enhancing the decolorization rate by irradiation, the enhancement was more significant at an initial pH near neutral. Concentration ratios of Fe(II) to sulfite higher than the optimum ratio (about 1:10) could inhibit the decolorization rate via the scavenging effect of sulfate or hydroxyl radicals. Semibatch experiments with multiple additions of Fe(II), sulfite, and Fe(II)–sulfite, respectively, showed that sulfite was more important in improving the decolorization efficiency of Orange II at higher concentration. However, removal of total organic carbon during the semibatch reaction by the Fe...
