The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fib...The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.展开更多
Biobased urea nowadays attracts increasing attention as a biomass resource with giant potential,which benefits from the development of biobased ammonia and ecological sanitation system.Urea is an ideal feedstock for c...Biobased urea nowadays attracts increasing attention as a biomass resource with giant potential,which benefits from the development of biobased ammonia and ecological sanitation system.Urea is an ideal feedstock for chemical industry and developing new urea-based polymer materials can take advantage of the urea resource.In this work,a class of renewable linear polyesters,namely polyisocyanuratoesters(PICEs)were synthesized from a urea-based monomer bis(2-carbomethoxyethyl)isocyanurate and biobased aliphatic diols.Compared with conventional aliphatic polyesters,PICEs containing isocyanurate rings in the polymer chain backbone exhibit outstanding flame retardancy that both PICE-4(the number‘4’refers to the number of methylene in diols,e.g.4 for butylene and 6 for hexylene)and PICE-6 have high limiting oxygen index values over 30%.In the UL 94 tests,PICE-6 reaches V-1 rating;while V-2 is found for PICE-10.All PICEs exhibit similar pyrolysis behavior that the temperatures of 5%weight loss are around 320°C.PICEs are found to have glass transition among 20°C-45°C.No crystallization behavior is observed without annealing except for PICE-10,which can crystallize even at room temperature.展开更多
Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray dif...Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.展开更多
Polyester(PET) was pre-activated by atmospheric air plasma and coated by various inorganic oxide nanoparticles(MOx) such as titanium dioxide(TiO2), zinc oxide(ZnO), and silicon oxide(SiO2), using poly(vinylidene fluor...Polyester(PET) was pre-activated by atmospheric air plasma and coated by various inorganic oxide nanoparticles(MOx) such as titanium dioxide(TiO2), zinc oxide(ZnO), and silicon oxide(SiO2), using poly(vinylidene fluoride)(PVDF) and chitosan(CT) as binders. The resulting PET-PVDF-MOx-CT composites were thermally compressed and then characterized by scanning electron microscopy, Fourier infrared spectroscopy, thermal gravimetric analysis, and flame retardancy(FR) ability tests. PET modifications resulted in more thermally stable and less harmful composites with weaker hazardous gas release. This was explained in terms of structure compaction that blocks pyrolysis gas emissions.CT incorporation was found to reduce the material susceptibility to oxidation. This judicious procedure also allowed improving flame retardancy ability, by lengthening the combustion delay and slowing the flame propagation. Chitosan also turned out to contribute to a possible synergy with the other polymers present in the synthesized materials. These results provide valuable data that allow understanding the FR phenomena and envisaging low-cost high FR materials from biodegradable raw materials.展开更多
文摘The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.
基金The authors are grateful for the financial supports of the National Science Foundation of China(21404040)the Fundamental Research Funds for the Central Universities(2015ZM053)the State Key Laboratory of Pulp and Paper Engineering(201538).
文摘Biobased urea nowadays attracts increasing attention as a biomass resource with giant potential,which benefits from the development of biobased ammonia and ecological sanitation system.Urea is an ideal feedstock for chemical industry and developing new urea-based polymer materials can take advantage of the urea resource.In this work,a class of renewable linear polyesters,namely polyisocyanuratoesters(PICEs)were synthesized from a urea-based monomer bis(2-carbomethoxyethyl)isocyanurate and biobased aliphatic diols.Compared with conventional aliphatic polyesters,PICEs containing isocyanurate rings in the polymer chain backbone exhibit outstanding flame retardancy that both PICE-4(the number‘4’refers to the number of methylene in diols,e.g.4 for butylene and 6 for hexylene)and PICE-6 have high limiting oxygen index values over 30%.In the UL 94 tests,PICE-6 reaches V-1 rating;while V-2 is found for PICE-10.All PICEs exhibit similar pyrolysis behavior that the temperatures of 5%weight loss are around 320°C.PICEs are found to have glass transition among 20°C-45°C.No crystallization behavior is observed without annealing except for PICE-10,which can crystallize even at room temperature.
基金Supported by the National Natural Science Foundation of China(51803057)Hebei Province Science Foundation for Youths(E2019508144)Fundamental Research Funds for the Central Universities(3142017099)。
文摘Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.
基金financially supported by the GEMTEX Laboratory-France
文摘Polyester(PET) was pre-activated by atmospheric air plasma and coated by various inorganic oxide nanoparticles(MOx) such as titanium dioxide(TiO2), zinc oxide(ZnO), and silicon oxide(SiO2), using poly(vinylidene fluoride)(PVDF) and chitosan(CT) as binders. The resulting PET-PVDF-MOx-CT composites were thermally compressed and then characterized by scanning electron microscopy, Fourier infrared spectroscopy, thermal gravimetric analysis, and flame retardancy(FR) ability tests. PET modifications resulted in more thermally stable and less harmful composites with weaker hazardous gas release. This was explained in terms of structure compaction that blocks pyrolysis gas emissions.CT incorporation was found to reduce the material susceptibility to oxidation. This judicious procedure also allowed improving flame retardancy ability, by lengthening the combustion delay and slowing the flame propagation. Chitosan also turned out to contribute to a possible synergy with the other polymers present in the synthesized materials. These results provide valuable data that allow understanding the FR phenomena and envisaging low-cost high FR materials from biodegradable raw materials.
