The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Jianfu Zhang - One of the best experts on this subject based on the ideXlab platform.
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tribological mechanical properties and morphology of Polyphenylene Oxide ultrahigh molecular weight polyethylene blends
Polymer-plastics Technology and Engineering, 2017Co-Authors: Qian Wu, Wenfei Li, Jianfu ZhangAbstract:ABSTRACTUltrahigh molecular weight polyethylene-g-polystyrene was synthesized as a compatibilizer through a suspension-grafting copolymerization method. Various weight ratios of Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blends were prepared by extruding, and mechanical properties, morphology as well as tribological behavior were investigated. Tensile strength, flexural strength, and Rockwell hardness increased with the increasing of the compatibilizer. Impact strength and antiwear properties of the blends were improved significantly by contrast to those of pure Polyphenylene Oxide. The Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blend of 90/10/0 compared with other ratios as an optimum ratio. In this case, the wear volume and friction coefficient of the blend were 2.6% of PPO and 45% lower than PPO, respectively.
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Tribological, Mechanical Properties, and Morphology of Polyphenylene Oxide/Ultrahigh Molecular Weight Polyethylene Blends
Polymer-plastics Technology and Engineering, 2016Co-Authors: Qian Wu, Wenfei Li, Jianfu ZhangAbstract:ABSTRACTUltrahigh molecular weight polyethylene-g-polystyrene was synthesized as a compatibilizer through a suspension-grafting copolymerization method. Various weight ratios of Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blends were prepared by extruding, and mechanical properties, morphology as well as tribological behavior were investigated. Tensile strength, flexural strength, and Rockwell hardness increased with the increasing of the compatibilizer. Impact strength and antiwear properties of the blends were improved significantly by contrast to those of pure Polyphenylene Oxide. The Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blend of 90/10/0 compared with other ratios as an optimum ratio. In this case, the wear volume and friction coefficient of the blend were 2.6% of PPO and 45% lower than PPO, respectively.
Peter Schouten - One of the best experts on this subject based on the ideXlab platform.
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Annual measurement of solar UVB at a reef site using a Polyphenylene Oxide dosimeter
2012Co-Authors: Nathan Downs, Alfio V. Parisi, Peter SchoutenAbstract:Numerous investigations detailed over the last thirty years have highlighted how solar UV (290-400 nm) can have a detrimental effect on coral health. It has also been postulated that coral bleaching is caused by a synergistic process between high water temperatures and increases in UV. As a consequence of its influence upon coral ecosystems, UV radiation must be monitored in underwater locations using an appropriate non-invasive measurement technique in order to better understand the damage it causes on both a macro and micro scale and provide solutions on how to adequately manage its impact. The high energy UVB waveband (290-320 nm) is believed to have the greatest negative influence on coral stress. This report details the employment of a simple, easily deployable UVB measuring dosimeter system based on Polyphenylene Oxide (PPO) at a coral reef location near Hervey Bay (25°17 S, 152°52′ E) over the interval of one year. Continual deployment of the PPO dosimeters measured a clear inverse correlation between tide level and UVB penetration, with the highest coral UVB exposures measured during the months of winter and spring (coinciding with typically lower tidal conditions during this time). This suggests that the UVB incident on Queensland coral reefs may not be strictly dependent on solar zenith angle (the Sun’s position in the sky), which is generally the primary factor in determining the extent of terrestrial UVB exposures. Further, this may mean that photo-damage incident on corals could be exacerbated in traditionally cooler months if current global warming trends continue.
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Utilising Polyphenylene Oxide for high exposure solar UVA dosimetry
Atmospheric Chemistry and Physics, 2008Co-Authors: David J. Turnbull, Peter SchoutenAbstract:A personal UV dosimeter that can quantitatively assess high exposure solar UVA exposures has been devel- oped. The chemical Polyphenylene Oxide has been previ- ously reported on its ability to measure high UVB exposures. This current research has found that Polyphenylene Oxide, cast in thin film form, is responsive to both the UVA and UVB parts of the solar spectrum. Further to this, the UVB wavelengths were filtered out with the use of mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates steadily when exposed to sunlight and can measure exposures of more than 20 MJ/m 2 of solar UVA radiation with an uncertainty level of no more than ±5%.
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Using the Polyphenylene Oxide dosimeter for extended underwater UV measurements
2008Co-Authors: Peter Schouten, David J. Turnbull, Alfio V. Parisi, Nathan DownsAbstract:The current global warming situation together with recent fluctuating trends in atmospheric ozone levels have resulted in changes occurring to the penetrative ability and distribution of the solar ultraviolet (UV) light field as measured in underwater locales such as in lakes and the ocean. The UV, in particular the UVB, has been shown by numerous studies in the past to have a detrimental effect on many forms of underwater life, ranging from the big to the small, each having their own special niche within the delicate marine ecosystem, which has direct consequences to our own life on the land. So it is extremely important that we measure and document the attributes of the UV underwater so we can enhance our understanding of its widespread effect upon the aquatic world. The underwater UV light environment has been measured in the past using a multitude of spectroradiometric and radiometric equipment. These instruments have been highly useful for taking underwater measurements of the UV sporadically over a short time frame. However, over long periods of time these spectroradiometers and radiometers become harder to employ, with sizeable amounts of time needed to accurately calibrate and correct them. This presentation provides measurements extracted from a year long measurement campaign conducted in a simulated sea water environment using a series of Polyphenylene Oxide (PPO) dosimeters immersed at varying depths and aligned to three different inclinations and four azimuths by using a custom built dosimeter submersible float (DSF). The results taken from this campaign were used to calculate an average diffuse attenuation coefficient (Kd) for the sea water in the UVB waveband. This Kd value was compared to another Kd value estimated using data taken using a spectrometer in the same water. Results taken from a long – term calibration completed using a prototype PPO dosimeter in conjunction with a neutral density filter (NDF) will also be presented.
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Utilising Polyphenylene Oxide for long term solar UVA dosimetry
2007Co-Authors: David J. Turnbull, Peter SchoutenAbstract:Exposure to UV radiation is known to be a causative factor in the induction of skin cancers and other sun-related disorders. Most acute responses of humans to UV exposure occur as a result of UVB (280 to 315 nm) exposures, as these wavelengths are highly sensitive in creating a human biological response. However, this does not mean that UVA radiation has no impact on human UV exposures and health. UVA can cause erythema in human skin, yet, the exposures required to create such a response is much larger than UVB radiation. UVA radiation penetrates much deeper into human skin tissue than UVB, resulting in impacts that are not as acute, taking many years to manifest. Past research has shown that UVA (315 to 400 nm) plays a significant role in human skin carcinogenesis. Studies have also shown that UVA plays an important role in skin damage, immune suppression, DNA damage, photoageing and wrinkling. Researchers at the University of Southern Queensland have developed a personal UV dosimeter that can quantitatively assess long term solar UVA exposures. The chemical Polyphenylene Oxide, cast in thin film form and which is responsive to both the UVA and UVB part of the spectrum was used and filtered with mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates reasonably slowly when exposed to sunlight and can measure exposures of more than 20 MJm-2 of solar UVA radiation with an uncertainty level of no more than ± 5%.
Yuan Hu - One of the best experts on this subject based on the ideXlab platform.
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mechanical thermal and flame retardant behaviors of thermoplastic polyether ester elastomer composites with Polyphenylene Oxide and aluminum hypophosphite
Polymer-plastics Technology and Engineering, 2017Co-Authors: Jing Zhan, Weizhao Hu, Lei Song, Yuan HuAbstract:ABSTRACTThe thermoplastic polyether–ester elastomer and Polyphenylene Oxide composite was prepared by the reactive extrusion method using 4,4′-methylene diphenyl diisocyanate as a chain extender, and then aluminum hypophosphite was added to further flame-retardant thermoplastic polyether–ester elastomer/Polyphenylene Oxide composite. The results show that 4,4′-methylene diphenyl diisocyanate can improve the compatibility of thermoplastic polyether–ester elastomer and Polyphenylene Oxide and strengthen the mechanical properties of thermoplastic polyether–ester elastomer/Polyphenylene Oxide composite. The addition of aluminum hypophosphite increases the storage modulus of the thermoplastic polyether–ester elastomer composites at the low-temperature region and significantly decreases the heat release rate of thermoplastic polyether–ester elastomer and thus improves its flame retardancy.
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Mechanical, Thermal, and Flame-Retardant Behaviors of Thermoplastic Polyether–Ester Elastomer Composites with Polyphenylene Oxide and Aluminum Hypophosphite
Polymer - Plastics Technology and Engineering, 2017Co-Authors: Jing Zhan, Xueli Liu, Liyan Ma, Weizhao Hu, Lei Song, Yuan HuAbstract:© 2017 Taylor & Francis. The thermoplastic polyether–ester elastomer and Polyphenylene Oxide composite was prepared by the reactive extrusion method using 4,4′-methylene diphenyl diisocyanate as a chain extender, and then aluminum hypophosphite was added to further flame-retardant thermoplastic polyether–ester elastomer/Polyphenylene Oxide composite. The results show that 4,4′-methylene diphenyl diisocyanate can improve the compatibility of thermoplastic polyether–ester elastomer and Polyphenylene Oxide and strengthen the mechanical properties of thermoplastic polyether–ester elastomer/Polyphenylene Oxide composite. The addition of aluminum hypophosphite increases the storage modulus of the thermoplastic polyether–ester elastomer composites at the low-temperature region and significantly decreases the heat release rate of thermoplastic polyether–ester elastomer and thus improves its flame retardancy.
Qian Wu - One of the best experts on this subject based on the ideXlab platform.
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tribological mechanical properties and morphology of Polyphenylene Oxide ultrahigh molecular weight polyethylene blends
Polymer-plastics Technology and Engineering, 2017Co-Authors: Qian Wu, Wenfei Li, Jianfu ZhangAbstract:ABSTRACTUltrahigh molecular weight polyethylene-g-polystyrene was synthesized as a compatibilizer through a suspension-grafting copolymerization method. Various weight ratios of Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blends were prepared by extruding, and mechanical properties, morphology as well as tribological behavior were investigated. Tensile strength, flexural strength, and Rockwell hardness increased with the increasing of the compatibilizer. Impact strength and antiwear properties of the blends were improved significantly by contrast to those of pure Polyphenylene Oxide. The Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blend of 90/10/0 compared with other ratios as an optimum ratio. In this case, the wear volume and friction coefficient of the blend were 2.6% of PPO and 45% lower than PPO, respectively.
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Tribological, Mechanical Properties, and Morphology of Polyphenylene Oxide/Ultrahigh Molecular Weight Polyethylene Blends
Polymer-plastics Technology and Engineering, 2016Co-Authors: Qian Wu, Wenfei Li, Jianfu ZhangAbstract:ABSTRACTUltrahigh molecular weight polyethylene-g-polystyrene was synthesized as a compatibilizer through a suspension-grafting copolymerization method. Various weight ratios of Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blends were prepared by extruding, and mechanical properties, morphology as well as tribological behavior were investigated. Tensile strength, flexural strength, and Rockwell hardness increased with the increasing of the compatibilizer. Impact strength and antiwear properties of the blends were improved significantly by contrast to those of pure Polyphenylene Oxide. The Polyphenylene Oxide/ultrahigh molecular weight polyethylene-g-polystyrene/ultrahigh molecular weight polyethylene blend of 90/10/0 compared with other ratios as an optimum ratio. In this case, the wear volume and friction coefficient of the blend were 2.6% of PPO and 45% lower than PPO, respectively.
David J. Turnbull - One of the best experts on this subject based on the ideXlab platform.
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Utilising Polyphenylene Oxide for high exposure solar UVA dosimetry
Atmospheric Chemistry and Physics, 2008Co-Authors: David J. Turnbull, Peter SchoutenAbstract:A personal UV dosimeter that can quantitatively assess high exposure solar UVA exposures has been devel- oped. The chemical Polyphenylene Oxide has been previ- ously reported on its ability to measure high UVB exposures. This current research has found that Polyphenylene Oxide, cast in thin film form, is responsive to both the UVA and UVB parts of the solar spectrum. Further to this, the UVB wavelengths were filtered out with the use of mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates steadily when exposed to sunlight and can measure exposures of more than 20 MJ/m 2 of solar UVA radiation with an uncertainty level of no more than ±5%.
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Utilising Polyphenylene Oxide for high exposure solar UVA dosimetry
Atmospheric Chemistry and Physics Discussions, 2008Co-Authors: David J. Turnbull, P. W. SchoutenAbstract:Abstract. Researchers at the University of Southern Queensland have developed a personal UV dosimeter that can quantitatively assess high exposure solar UVA exposures. The chemical Polyphenylene Oxide has been previously reported on its ability to measure high UVB exposures. This current research has found that Polyphenylene Oxide, cast in thin film form, is responsive to both the UVA and UVB parts of the solar spectrum. Further to this, the UVB wavelengths were filtered out with the use of mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates steadily when exposed to sunlight and can measure exposures of more than 20 MJ/m2 of solar UVA radiation with an uncertainty level of no more than ±5%.
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Using the Polyphenylene Oxide dosimeter for extended underwater UV measurements
2008Co-Authors: Peter Schouten, David J. Turnbull, Alfio V. Parisi, Nathan DownsAbstract:The current global warming situation together with recent fluctuating trends in atmospheric ozone levels have resulted in changes occurring to the penetrative ability and distribution of the solar ultraviolet (UV) light field as measured in underwater locales such as in lakes and the ocean. The UV, in particular the UVB, has been shown by numerous studies in the past to have a detrimental effect on many forms of underwater life, ranging from the big to the small, each having their own special niche within the delicate marine ecosystem, which has direct consequences to our own life on the land. So it is extremely important that we measure and document the attributes of the UV underwater so we can enhance our understanding of its widespread effect upon the aquatic world. The underwater UV light environment has been measured in the past using a multitude of spectroradiometric and radiometric equipment. These instruments have been highly useful for taking underwater measurements of the UV sporadically over a short time frame. However, over long periods of time these spectroradiometers and radiometers become harder to employ, with sizeable amounts of time needed to accurately calibrate and correct them. This presentation provides measurements extracted from a year long measurement campaign conducted in a simulated sea water environment using a series of Polyphenylene Oxide (PPO) dosimeters immersed at varying depths and aligned to three different inclinations and four azimuths by using a custom built dosimeter submersible float (DSF). The results taken from this campaign were used to calculate an average diffuse attenuation coefficient (Kd) for the sea water in the UVB waveband. This Kd value was compared to another Kd value estimated using data taken using a spectrometer in the same water. Results taken from a long – term calibration completed using a prototype PPO dosimeter in conjunction with a neutral density filter (NDF) will also be presented.
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Utilising Polyphenylene Oxide for long term solar UVA dosimetry
2007Co-Authors: David J. Turnbull, Peter SchoutenAbstract:Exposure to UV radiation is known to be a causative factor in the induction of skin cancers and other sun-related disorders. Most acute responses of humans to UV exposure occur as a result of UVB (280 to 315 nm) exposures, as these wavelengths are highly sensitive in creating a human biological response. However, this does not mean that UVA radiation has no impact on human UV exposures and health. UVA can cause erythema in human skin, yet, the exposures required to create such a response is much larger than UVB radiation. UVA radiation penetrates much deeper into human skin tissue than UVB, resulting in impacts that are not as acute, taking many years to manifest. Past research has shown that UVA (315 to 400 nm) plays a significant role in human skin carcinogenesis. Studies have also shown that UVA plays an important role in skin damage, immune suppression, DNA damage, photoageing and wrinkling. Researchers at the University of Southern Queensland have developed a personal UV dosimeter that can quantitatively assess long term solar UVA exposures. The chemical Polyphenylene Oxide, cast in thin film form and which is responsive to both the UVA and UVB part of the spectrum was used and filtered with mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates reasonably slowly when exposed to sunlight and can measure exposures of more than 20 MJm-2 of solar UVA radiation with an uncertainty level of no more than ± 5%.