The Experts below are selected from a list of 21849 Experts worldwide ranked by ideXlab platform
Zhengping Fang - One of the best experts on this subject based on the ideXlab platform.
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thermal degradation and Flame Retardancy properties of abs lignin effects of lignin content and reactive compatibilization
Thermochimica Acta, 2011Co-Authors: Pingan Song, Shenyuan Fu, Zhengping Fang, Qian Wu, Jiewang YeAbstract:Abstract Effects of alkali lignin incorporation and in situ reactive compatibilization on the thermal stability and Flame Retardancy of ABS were investigated. Morphology observations show that lignin can form submicron dispersed phases in ABS matrix regardless of compatibilization. Thermal analyses show that lignin will cause a slight thermal instability of ABS due to its relatively lower thermal stability, and compatibilization reaction has little effluence on that. However, lignin can slow the degradation process and increase the char residue of ABS with increasing lignin loading, and the compatibilization does not markedly affect them. Cone calorimeter tests demonstrate that lignin can significantly reduce the heat release rate, and slow the combustion process of ABS, e.g., 20 wt% lignin causing a 32% reduction in peak heat release rate (PHRR). The compatibilization can further reduce the flammability of ABS due to the improved char layer. The char residue analyses indicate that the formation of protective char layer of lignin is primarily responsible for the enhanced Flame Retardancy.
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Flame retardant wrapped carbon nanotubes for simultaneously improving the Flame Retardancy and mechanical properties of polypropylene
Journal of Materials Chemistry, 2008Co-Authors: Yan Zhang, Pingan Song, Zhengping Fang, Lihua XuAbstract:Covalently functionalized carbon nanotubes (CNTs) wrapped in intumescent Flame retardant were successfully fabricated and characterized. By adjusting the ratio of CNTs and Flame retardant, the diameter of the functionalized CNTs was effectively controlled to 20–90 nm. Compared with pristine CNTs, the functionalized CNTs are better dispersed in polypropylene (PP) due to the in situ compatibilization reaction between the active groups of the intumescent Flame retardant on the CNT surface and the maleic anhydride groups in the compatibilizer, maleic anhydride-grafted polypropylene (PPMA). Incorporating the functionalized CNTs could confer outstanding Flame Retardancy on PP/PPMA, and considerably enhance the mechanical properties of the polymeric materials due to the improved interfacial adhesion and stress transfer. Therefore, use of intumescent Flame-retardant-wrapped carbon nanotubes and in situ compatibilization are promising strategies for simultaneously improving the Flame Retardancy and mechanical properties of polymeric materials.
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synergistic effect of carbon nanotube and clay for improving the Flame Retardancy of abs resin
Nanotechnology, 2007Co-Authors: Lifang Tong, Z Xu, Zhengping FangAbstract:Synergistic effect between multi-walled carbon nanotubes (MWNTs) and clay on improving the Flame Retardancy of acrylonitrile–butadiene–styrene (ABS) resin was studied. Flammability properties measured by a cone calorimeter revealed that incorporation of clay and MWNTs into ABS resin significantly reduced the peak heat release rate (PHRR) and slowed down the whole combustion process compared to the individually filled system based on clay or MWNTs. The Flame Retardancy of the ABS/clay/MWNTs nanocomposites was strongly affected by the formation of a network structure. Linear viscoelastic properties of the ABS nanocomposites showed that the coexistence of clay and MWNTs can enhance the network structure which can hinder the movement of polymer chains and improve Flame Retardancy. From transmission electron microscope analysis, MWNTs were shortened after combustion and there was no significant change in their diameters. For chars of ABS/clay/MWNTs nanocomposites, some MWNTs ran across between clay layers, indicating a strong interaction existed between clay and MWNTs. The existence of clay enhanced the graphitization degree of MWNTs during combustion. Clay can assist the elimination of dislocations and defects and the rearrangement of crystallites. Al2O3, one of the components of clay, acts as the catalyst of graphitization.
Pingan Song - One of the best experts on this subject based on the ideXlab platform.
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functionalized lignin by grafting phosphorus nitrogen improves the thermal stability and Flame Retardancy of polypropylene
Polymer Degradation and Stability, 2012Co-Authors: Youming Yu, Shenyuan Fu, Pingan Song, Fengzhu Lu, Qiang Wu, Jiewang YeAbstract:Improving the thermal stability and Flame Retardancy of polymers remains a great challenge. Although lignin has been used as a Flame retardant for polymers, its Flame Retardancy effect is usually limited. We, herein, successfully modified alkali lignin by chemically grafting two Flame retardant elements, phosphorous and nitrogen, via a three-step reaction. Compared with lignin, modified lignin (PN-lignin) exhibits a much higher char-forming ability with a char of 61.4 wt% (40.7 wt% for lignin) at 600°C in N 2. PN-lignin confers a much higher thermal stability and amount of char residue on polypropylene relative to lignin. Moreover, PN-lignin further reduces the heat release rate and slows the combustion process, indicating a better Flame Retardancy. The continuous and intact char layer mainly contributes to the improved Flame Retardancy. This strategy not only provides a novel method for Flame retarding polymeric materials, but greatly extends the comprehensive utilization of industrial lignin.
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thermal degradation and Flame Retardancy properties of abs lignin effects of lignin content and reactive compatibilization
Thermochimica Acta, 2011Co-Authors: Pingan Song, Shenyuan Fu, Zhengping Fang, Qian Wu, Jiewang YeAbstract:Abstract Effects of alkali lignin incorporation and in situ reactive compatibilization on the thermal stability and Flame Retardancy of ABS were investigated. Morphology observations show that lignin can form submicron dispersed phases in ABS matrix regardless of compatibilization. Thermal analyses show that lignin will cause a slight thermal instability of ABS due to its relatively lower thermal stability, and compatibilization reaction has little effluence on that. However, lignin can slow the degradation process and increase the char residue of ABS with increasing lignin loading, and the compatibilization does not markedly affect them. Cone calorimeter tests demonstrate that lignin can significantly reduce the heat release rate, and slow the combustion process of ABS, e.g., 20 wt% lignin causing a 32% reduction in peak heat release rate (PHRR). The compatibilization can further reduce the flammability of ABS due to the improved char layer. The char residue analyses indicate that the formation of protective char layer of lignin is primarily responsible for the enhanced Flame Retardancy.
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Flame retardant wrapped carbon nanotubes for simultaneously improving the Flame Retardancy and mechanical properties of polypropylene
Journal of Materials Chemistry, 2008Co-Authors: Yan Zhang, Pingan Song, Zhengping Fang, Lihua XuAbstract:Covalently functionalized carbon nanotubes (CNTs) wrapped in intumescent Flame retardant were successfully fabricated and characterized. By adjusting the ratio of CNTs and Flame retardant, the diameter of the functionalized CNTs was effectively controlled to 20–90 nm. Compared with pristine CNTs, the functionalized CNTs are better dispersed in polypropylene (PP) due to the in situ compatibilization reaction between the active groups of the intumescent Flame retardant on the CNT surface and the maleic anhydride groups in the compatibilizer, maleic anhydride-grafted polypropylene (PPMA). Incorporating the functionalized CNTs could confer outstanding Flame Retardancy on PP/PPMA, and considerably enhance the mechanical properties of the polymeric materials due to the improved interfacial adhesion and stress transfer. Therefore, use of intumescent Flame-retardant-wrapped carbon nanotubes and in situ compatibilization are promising strategies for simultaneously improving the Flame Retardancy and mechanical properties of polymeric materials.
Jiewang Ye - One of the best experts on this subject based on the ideXlab platform.
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functionalized lignin by grafting phosphorus nitrogen improves the thermal stability and Flame Retardancy of polypropylene
Polymer Degradation and Stability, 2012Co-Authors: Youming Yu, Shenyuan Fu, Pingan Song, Fengzhu Lu, Qiang Wu, Jiewang YeAbstract:Improving the thermal stability and Flame Retardancy of polymers remains a great challenge. Although lignin has been used as a Flame retardant for polymers, its Flame Retardancy effect is usually limited. We, herein, successfully modified alkali lignin by chemically grafting two Flame retardant elements, phosphorous and nitrogen, via a three-step reaction. Compared with lignin, modified lignin (PN-lignin) exhibits a much higher char-forming ability with a char of 61.4 wt% (40.7 wt% for lignin) at 600°C in N 2. PN-lignin confers a much higher thermal stability and amount of char residue on polypropylene relative to lignin. Moreover, PN-lignin further reduces the heat release rate and slows the combustion process, indicating a better Flame Retardancy. The continuous and intact char layer mainly contributes to the improved Flame Retardancy. This strategy not only provides a novel method for Flame retarding polymeric materials, but greatly extends the comprehensive utilization of industrial lignin.
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thermal degradation and Flame Retardancy properties of abs lignin effects of lignin content and reactive compatibilization
Thermochimica Acta, 2011Co-Authors: Pingan Song, Shenyuan Fu, Zhengping Fang, Qian Wu, Jiewang YeAbstract:Abstract Effects of alkali lignin incorporation and in situ reactive compatibilization on the thermal stability and Flame Retardancy of ABS were investigated. Morphology observations show that lignin can form submicron dispersed phases in ABS matrix regardless of compatibilization. Thermal analyses show that lignin will cause a slight thermal instability of ABS due to its relatively lower thermal stability, and compatibilization reaction has little effluence on that. However, lignin can slow the degradation process and increase the char residue of ABS with increasing lignin loading, and the compatibilization does not markedly affect them. Cone calorimeter tests demonstrate that lignin can significantly reduce the heat release rate, and slow the combustion process of ABS, e.g., 20 wt% lignin causing a 32% reduction in peak heat release rate (PHRR). The compatibilization can further reduce the flammability of ABS due to the improved char layer. The char residue analyses indicate that the formation of protective char layer of lignin is primarily responsible for the enhanced Flame Retardancy.
Edward D. Weil - One of the best experts on this subject based on the ideXlab platform.
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Flame Retardancy of thermoplastic polyesters—a review of the recent literature
Polymer International, 2020Co-Authors: Sergei V. Levchik, Edward D. WeilAbstract:An overview is presented of the literature on the Flame Retardancy of thermoplastic polyesters, especially poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT). The main focus is on publications of the last fifteen years; however, some earlier work of major importance is discussed as well. Because PET and PBT almost totally convert to volatile fragments upon exposure to heat, providing fuel to the Flame, it is a challenging task to Flame-retard these polymers. Although many of the commercially available systems for Flame Retardancy of PET and PBT consist of a halogen-containing additive and a synergist, more recent publications and patents emphasize halogen-free, particularly phosphorus-based systems. Several phosphorus-based additive or reactive systems are well-established for use in PET textiles, and phosphorus-based additives have recently been introduced for PBT. Copyright © 2004 Society of Chemical Industry
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overview of recent developments in the Flame Retardancy of polycarbonates
Polymer International, 2005Co-Authors: Sergei V. Levchik, Edward D. WeilAbstract:This paper presents an overview of the recent literature on Flame Retardancy of polycarbonate (PC) and polycarbonate-based resins. A brief survey of the major mechanisms of thermal decomposition of PC is also presented because it gives insight in the mechanisms of Flame retardant action. Mostly industrial laboratories are involved in the development of new Flame retardants for PC and, to a much lesser extent, academic laboratories are doing research on the mechanistic aspects of Flame Retardancy. The number of patents published annually on the Flame Retardancy of PC and its blends significantly exceeds the number of patents on Flame Retardancy of any other polymer. Because PC is a naturally high charring polymer, the condensed phase active Flame retardants, in particular phosphorus-based ones, are widely used in PC-based blends. Plain PC can pass stringent Flame retardant tests with very low additions of some sulfur- or silicone-based Flame retardants. Copyright © 2005 Society of Chemical Industry
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Flame Retardancy of thermoplastic polyesters a review of the recent literature
Polymer International, 2005Co-Authors: Sergei V. Levchik, Edward D. WeilAbstract:An overview is presented of the literature on the Flame Retardancy of thermoplastic polyesters, especially poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT). The main focus is on publications of the last fifteen years; however, some earlier work of major importance is discussed as well. Because PET and PBT almost totally convert to volatile fragments upon exposure to heat, providing fuel to the Flame, it is a challenging task to Flame-retard these polymers. Although many of the commercially available systems for Flame Retardancy of PET and PBT consist of a halogen-containing additive and a synergist, more recent publications and patents emphasize halogen-free, particularly phosphorus-based systems. Several phosphorus-based additive or reactive systems are well-established for use in PET textiles, and phosphorus-based additives have recently been introduced for PBT. Copyright © 2004 Society of Chemical Industry
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Mechanisms and modes of action in Flame Retardancy of polymers
Fire Retardant Materials, 2001Co-Authors: Menachem Lewin, Edward D. WeilAbstract:A review with 202 refs. on the principles, mechanisms and modes of action relating to Flame Retardancy in polymers. [on SciFinder(R)]
Shenyuan Fu - One of the best experts on this subject based on the ideXlab platform.
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functionalized lignin by grafting phosphorus nitrogen improves the thermal stability and Flame Retardancy of polypropylene
Polymer Degradation and Stability, 2012Co-Authors: Youming Yu, Shenyuan Fu, Pingan Song, Fengzhu Lu, Qiang Wu, Jiewang YeAbstract:Improving the thermal stability and Flame Retardancy of polymers remains a great challenge. Although lignin has been used as a Flame retardant for polymers, its Flame Retardancy effect is usually limited. We, herein, successfully modified alkali lignin by chemically grafting two Flame retardant elements, phosphorous and nitrogen, via a three-step reaction. Compared with lignin, modified lignin (PN-lignin) exhibits a much higher char-forming ability with a char of 61.4 wt% (40.7 wt% for lignin) at 600°C in N 2. PN-lignin confers a much higher thermal stability and amount of char residue on polypropylene relative to lignin. Moreover, PN-lignin further reduces the heat release rate and slows the combustion process, indicating a better Flame Retardancy. The continuous and intact char layer mainly contributes to the improved Flame Retardancy. This strategy not only provides a novel method for Flame retarding polymeric materials, but greatly extends the comprehensive utilization of industrial lignin.
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thermal degradation and Flame Retardancy properties of abs lignin effects of lignin content and reactive compatibilization
Thermochimica Acta, 2011Co-Authors: Pingan Song, Shenyuan Fu, Zhengping Fang, Qian Wu, Jiewang YeAbstract:Abstract Effects of alkali lignin incorporation and in situ reactive compatibilization on the thermal stability and Flame Retardancy of ABS were investigated. Morphology observations show that lignin can form submicron dispersed phases in ABS matrix regardless of compatibilization. Thermal analyses show that lignin will cause a slight thermal instability of ABS due to its relatively lower thermal stability, and compatibilization reaction has little effluence on that. However, lignin can slow the degradation process and increase the char residue of ABS with increasing lignin loading, and the compatibilization does not markedly affect them. Cone calorimeter tests demonstrate that lignin can significantly reduce the heat release rate, and slow the combustion process of ABS, e.g., 20 wt% lignin causing a 32% reduction in peak heat release rate (PHRR). The compatibilization can further reduce the flammability of ABS due to the improved char layer. The char residue analyses indicate that the formation of protective char layer of lignin is primarily responsible for the enhanced Flame Retardancy.