Ce2O3对APP-PER-MA膨胀阻燃体系热解过程的协效作用

采用热重分析和红外光谱技术研究了氧化铈（Ce2O3）对以聚磷酸铵(APP)为酸源、季戊四醇(PER)为炭源、蜜胺（MA）为气源的经典膨胀型阻燃剂（IFR）热分解性能的影响。 结果表明,300~400 ℃时Ce2O3的存在加快了体系的分解和无机酸的生成速度,改变了IFR热解发生的时间,但是并没有从根本上改变热解过程;Ce2O3的添加使IFR阻燃剂第一阶段的热解活化能由65.73 kJ/mol提高至73.47 kJ/mol,第二、三、四阶段的热解活化能分别由167.46、135.13、141.34 kJ/mol降低至85.25、96.08、58.18 kJ/mol,并对IFR分解各阶段残留量有很大影响。     

Synthesis,Crystal Structure and Thermal Properties of N,N＇-Bis（5,5-dimethyl- 2-phospha-2-thio-1,3-dioxan-2-yl） Ethylene Diamine

The title compound N,N＇-bis（5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl） ethylene diamine （DPTDEDA, C12H26N2O4P2S2） was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylenediamine, and characterized by elemental analysis, IR and ^1H NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction analysis and the thermal property was analyzed by TG analysis. The crystal structure belongs to monoclinic, space group P21/c, with a = 14.557（16）, b = 11.299（12）, c = 12.163（13）A,β = 98.707（19）^o, Dc = 1.305 g/cm^3, Z = 4, γ = 0.71073A,μ（MoKa） = 0.447 mm^-1, Mr = 388.41, V = 1977（4）A3, F（000） = 824, S = 1.107, the final R = 0.0478 and wR = 0.0810 for 1738 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the crystal structure is centrosymmetrically distributed through 1,2-ethylenediamine to join two distorted six-membered rings. The weak N-H…S interactions are observed and link the molecules into sheets. TG analysis shows that the title compound has good thermal stability and char-forming capability, which are required for an excellent intumescent fire retardant.     

三季戊四醇亚磷酸酯阻燃剂的合成及应用研究

以三季戊四醇(TPE)、亚磷酸三苯酯(TPP)为反应原料,氢氧化钠为催化剂,采用非溶剂酯交换一步法合成了三季戊四醇亚磷酸酯膨胀型阻燃剂。用红外光谱与元素分析初步确定了三季戊四醇亚磷酸酯类的物质。热分析表明,10％的失重所对应的温度为122℃,50％的失重对应的温度为371℃;其失重速率最大时的峰顶温度为329℃;在500℃时的成炭量高达40％。以三季戊四醇亚磷酸酯和三聚氰胺复配阻燃的环氧树脂,添加量为19％时其极限氧指数(LOI)为35％,通过了UL94V-0级,表明该阻燃剂具有优良的阻燃性能。     

膨胀型环状类磷酸酯蜜胺盐阻燃剂的合成及阻燃聚丙烯的结构与性能

以双季戊四醇、三季戊四醇、多聚磷酸、五氧化二磷和三聚氰胺为原料,合成了膨胀型环状类磷酸酯蜜胺盐阻燃剂,并与聚丙烯共混制成阻燃聚丙烯.红外分析表明该阻燃剂具有环状结构.通过扫描电镜和X射线衍射对阻燃聚丙烯进行了结构分析和表面纹理的表征.实验结果表明：该阻燃剂阻燃性能良好,但在聚丙烯中的分散性较差;用甲基纤维素对该阻燃剂进行表面化学修饰以后,该阻燃剂在聚丙烯中的分散性及阻燃材料的机械性能得到了明显的改善.     

Study on combustion property and synergistic effect of intumescent flame retardant styrene butadiene rubber with metallic oxides

Effect of metallic oxides on flame retardancy and the thermal stability of styrene butadiene rubber (SBR) composites based on ammonium polyphosphate (APP) and pentaerythritol (PER) was studied by the limiting oxygen index (LOI), UL 94, the cone calorimeter tests, and thermogravimetry analysis (TGA), respectively. Scanning electron microscopy (SEM) and wide‐angle X‐ray diffraction (WAXD) were used to analyze the morphological structure and the component of the residue chars formed from the SBR composites accordingly. The addition of zirconium dioxide (ZrO₂) at a loading of 3.4 phr could improve the UL 94 test rating of the composite to V‐0. The TGA data illustrated that the metallic oxides could enhance the thermal stability of the SBR/Intumescent flame retardant additives (IFRs) composites at high temperature and increase the residue. Cone calorimeter test gave much clear evidence that the incorporation of ZrO₂ into SBR/IFRs composites resulted in the significant deduction of the heat release rate (HRR) values, and the SEM images showed that the char layers of the composites containing the metallic oxides became more compact. From the WAXD pattern, zirconium phosphate (ZrP₂O₇) may be formed by the reaction between ZrO₂ and APP. Due to the addition of ZrO₂ and the formation of ZrP₂O₇, the flame retardancy of the composite was improved. Copyright © 2009 John Wiley & Sons, Ltd.     

Photocrosslinking and related properties of intumescent flame‐retardant LLDPE/EVA/IFR blends

The photoinitiated crosslinking of halogen‐free flame retarded linear low density polyethylene/poly(ethylene‐co‐vinyl acetate) blends (LLDPE/EVA) with the intumescent flame retardant (IFR) of phosphorous‐nitrogen compound (NP) in the presence of photoinitiator and crosslinker and their characterization of related properties have been investigated by gel determination, heat extension test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), Fourier transfer infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), mechanical properties measurements, limiting oxygen index (LOI), UL‐94, and water resistance test. The data from the gel content and heat extension rate (HER) show that the LLDPE/EVA/IFR blends filled with NP are readily crosslinked to a gel content of above 75% and the HER values reach about 50% by UV‐irradiation of 5 sec under suitable amount of photoinitiator and crosslinker. The data obtained from the CCT and LOI indicate that photocrosslinking can considerably decrease the heat release rates (HRR) by 10–15%, prolongate the combustion time, and increase two LOI values for the LLDPE/EVA/NP blends UV irradiated for 5 sec. The results from TGA and the dynamic FTIR spectra give the evidence that the photocrosslinked LLDPE/EVA/NP samples show slower thermal degradation rate and higher thermo‐oxidative degradation temperature than the uncrosslinked LLDPE/EVA/NP samples. The morphological structures of charred residues observed by SEM give the positive evidence that the compact charred layers formed from the photocrosslinked LLDPE/EVA/NP samples play an important role in the enhancement of flame retardant and thermal properties. The data from the mechanical tests and water‐resistant measurements show that photocrosslinking can considerably improve the mechanical and water‐resistant properties of LLDPE/EVA/NP samples. Copyright © 2011 John Wiley & Sons, Ltd.     

Fire hazard suppression of intumescent flame retardant polypropylene based on a novel Ni‐containing char‐forming agent

Reducing the fire hazard of polypropylene (PP) is an important research direction in the fields of fire safety materials. In this article, a novel Ni‐containing char‐forming agent (TTPN) was successfully synthesized, using tris(2‐hydroxyethyl) isocyanurate (THEIC), terephthalic acid, and nickel dihydrogen phosphate. Then, TTPN was combined with the silica‐gel microencapsulated ammonium polyphosphate (OS‐MCAPP) to prepare intumescent flame retardant PP composites. From the results of the limiting oxygen index (LOI) test and cone calorimeter, the composite containing 30% IFR (OS‐MCAPP: TTPN = 3:2) shows the highest LOI value of 33.5%, and its peak heat release rate is 275.5 kWm^?2, decreased by 79.0% and 37.4% than those of pure PP and the composite containing the char‐forming agent without Ni. Meanwhile, the composite containing TTPN present the best smoke and CO₂/CO suppression. The results indicate that TTPN has an excellent ability to dramatically reduce the fire hazard of PP.     

An Exactly Solvable One-Dimensional Electron-Phonon System

An extended Tomonaga-Luttinger model including for-ward scattering both from electron-electron and electron-pho-non interaction is solved exactly using bosonization techniques. We calculate correlation functions for the relevant instabilities and give a phase diagram.     

Effect of Modified Intumescent Flame Retardant via Surfactant/Polyacrylate Latex on Properties of Intumescent Flame Retardant ABS Composites

In order to prepare intumescent flame retardant acrylonitrile-butadiene-styrene (ABS) composites with only a small decrease in their mechanical properties, we investigated the effect of adding an elastomeric polyacrylate latex and the surfactant TX-10 phosphate to modify the ammonium polyphosphate, melamine, and calcium 3-hydroxy-2, 2-bis(hydroxymethyl) propyl phosphate normally used, which resulted in an intumescent flame retardant composite (IFRC) powder with the aim of improving compatibility. These ABS/IFRC composites were compared with standard material containing unmodified intumescent flame retardant (NIFR) by investigating their thermal properties, melt characteristics, mechanical properties, and microstructure. The data showed that the glass transition temperature of the ABS/IFRC composites decreased slightly in all cases, the complex viscosity of the ABS/IFRC composites was remarkably reduced, and the mechanical properties improved in comparison with the material containing NIFR. A slight increase in impact strength retention, as well as a remarkable increase in tensile and flexural strength retention of ABS/IFRC, was achieved due to superior compatibility between ABS and IFRC in comparison with ABS/NIFR.     

Synthesis, Crystal Structure and Thermal Properties of N,N′-Bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) Ethylene Diamine

The title compound N,N′-bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) ethylene diamine (DPTDEDA, C12H26N2O4P2S2) was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylenediamine, and characterized by elemental analysis, IR and 1H NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction analysis and the thermal property was analyzed by TG analysis. The crystal structure belongs to monoclinic, space group P21/c, with a = 14.557(16), b = 11.299(12), c = 12.163(13) , β = 98.707(19)°, Dc = 1.305 g/cm3, Z = 4, λ = 0.71073 , μ(MoKα) = 0.447 mm-1, Mr = 388.41, V = 1977(4) 3, F(000) = 824, S = 1.107, the final R = 0.0478 and wR = 0.0810 for 1738 observed reflections (I > 2σ(I)). X-ray analysis reveals that the crystal structure is centrosymmetrically distributed through 1,2-ethylenediamine to join two distorted six-membered rings. The weak N–H···S interactions are observed and link the molecules into sheets. TG analysis shows that the title compound has good thermal stability and char-forming capability, which are required for an excellent intumescent fire retardant.