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Yunjun Luo - One of the best experts on this subject based on the ideXlab platform.
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flame retardancy and thermal degradation mechanism of a novel post chain Extension flame retardant waterborne polyurethane
Polymer Degradation and Stability, 2016Co-Authors: Yunjun LuoAbstract:A series of novel flame-retardant waterborne polyurethanes (AWPUs) with a phosphorus-containing flame retardant diamine (Bis (4-aminophenoxy) phenyl phosphine oxide (BPPO)) were synthesized by the method of post-chain Extension technique and the structure was confirmed by FTIR and NMR. The phosphorus-containing chain extender improved the tensile strength but decreased the elongation at break. Influences of BPPO on the thermal degradation properties and flame retardancy of AWPU's were investigated by thermal gravimetric analysis (TGA), limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test (CCT). TGA results showed that the post-chain Extension of BPPO promoted the degradation process and reduced the thermal stability of AWPUs. LOI, UL-94 and CCT indicated that the flame retardancy was improved with the increase of BPPO. When the chain Extension Ratio reached 100%, the LOI increased up to 30.1%, PHRR and THR were reduced by 57.1% and 41.6% respectively. The thermal degradation mechanism of AWPUs with chain Extension of BPPO was studied by several measurements such as TGA-FTIR, in situ FTIR, SEM and EDS analysis, the results showed that the decomposition of AWPUs were divided into three stages. First of all, BPPO decomposed, and then the degradation of hard segment of AWPUs took place followed by the degradation of soft segment of AWPUs.
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synthesis and characterization of novel post chain Extension flame retardant waterborne polyurethane
RSC Advances, 2015Co-Authors: Chunpeng Chai, Jialun Lin, Yunjun LuoAbstract:A series of novel flame-retardant waterborne polyurethanes with a phosphorus-containing flame retardant diamine (AWPUs) were synthesized by the method of post-chain Extension and the effect of the chain extender on the properties of AWPU dispersions were investigated. The results revealed that the chain Extension increased the molecular weight and the molecular weight distribution. The emulsions AWPUs still maintained their stability and particle sizes increased after post-chain Extension. AWPUs with a post-chain Extension of bis(4-aminophenoxy)phenyl phosphine oxide were successfully prepared and characterized using FTIR and NMR analysis. The hydrogen bonds in hard segments and the phase sepaRation between hard segments and soft segments were enhanced. Moreover, the phosphorus-containing chain extender improved the tensile strength but decreased the elongation at break. With the increase of chain Extension Ratio, the glass transition temperature for hard segments showed an increasing trend but the glass transition temperature for soft segments showed a decreasing trend. The phosphorus-containing chain extender reduced the thermal stability of AWPUs and favored the degradation of AWPUs. Finally, the flame retardancy was improved with the flame-retardant extender added.
Fangxiao Guan - One of the best experts on this subject based on the ideXlab platform.
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
Lianyun Yang - One of the best experts on this subject based on the ideXlab platform.
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
Elshad Allahyarov - One of the best experts on this subject based on the ideXlab platform.
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
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crystal orientation and temperature effects on double hysteresis loop behavior in a poly vinylidene fluoride co trifluoroethylene co chlorotrifluoroethylene graft polystyrene graft copolymer
Macromolecules, 2013Co-Authors: Lianyun Yang, Elshad Allahyarov, Fangxiao GuanAbstract:Recently, double hysteresis loop (DHL) behavior, which is advantageous for the high energy density and low loss dielectric application, was achieved in a poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-polystyrene [P(VDF-TrFE-CTFE)-g-PS(14%)] graft copolymer due to the nanoconfinement effect. In this work, we continued to investigate the crystal orientation and temperature effects on the DHL behavior of this graft copolymer. Based on the electric displacement–electric field (D–E) study, crystal orientation had a profound effect on its electrical behavior. For the nonoriented sample, dielectric instead of ferroelectric behavior was observed. After uniaxial stretching, DHLs gradually developed in the oriented films upon increasing the Extension Ratio. For a fully stretched film, the DHL behavior was stable below 75 °C but gradually disappeared above 100 °C due to enhanced dc conduction and impurity ion migRational loss at elevated temperatures. After subtracting the dc conduc...
Chunpeng Chai - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel post chain Extension flame retardant waterborne polyurethane
RSC Advances, 2015Co-Authors: Chunpeng Chai, Jialun Lin, Yunjun LuoAbstract:A series of novel flame-retardant waterborne polyurethanes with a phosphorus-containing flame retardant diamine (AWPUs) were synthesized by the method of post-chain Extension and the effect of the chain extender on the properties of AWPU dispersions were investigated. The results revealed that the chain Extension increased the molecular weight and the molecular weight distribution. The emulsions AWPUs still maintained their stability and particle sizes increased after post-chain Extension. AWPUs with a post-chain Extension of bis(4-aminophenoxy)phenyl phosphine oxide were successfully prepared and characterized using FTIR and NMR analysis. The hydrogen bonds in hard segments and the phase sepaRation between hard segments and soft segments were enhanced. Moreover, the phosphorus-containing chain extender improved the tensile strength but decreased the elongation at break. With the increase of chain Extension Ratio, the glass transition temperature for hard segments showed an increasing trend but the glass transition temperature for soft segments showed a decreasing trend. The phosphorus-containing chain extender reduced the thermal stability of AWPUs and favored the degradation of AWPUs. Finally, the flame retardancy was improved with the flame-retardant extender added.
