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1.
混合热计算和FTIR分析表明,聚对苯二甲酸乙二酯(PET)与聚苯膦酸二苯砜酯(PSPPP)具有一定的相容性,不同PSPPP含量的PET均具有较高的热稳定性,PET/PSPPP体系的阻燃性随阻燃剂PSPPP含量的增加而提高,PSPPP重量百分含量5%(下同)的阻燃PET体系的LOI值可达到30.1,由不同分子量的PSPPP构成的各种配比的PET体系,其表现粘度随切变速率的增大而降低,PSPPP的分子  相似文献   

2.
1 前言PET(聚对苯二甲酸乙二醇酯 )由于具有优良的综合性能 ,被广泛地应用于合成纤维、薄膜和工程塑料等领域 ,但由于它的可燃性 ,在火灾事故中 ,由其着火所致占有较大比例 ,因此它的阻燃化更加引起了世界范围内学者的广泛关注[1 ] 。由于磷是对聚酯的最有效阻燃元素 ,采用共聚法制备含磷PET的报道较多 ,也有关于其热降解动力学研究的报道[2~ 1 0 ] 。但本文所采用的单体羟基苯氧膦丙酸 (CEPP)和PET共聚所得产物的热降解动力学研究 ,尚未见报道。研究该种含磷PET的热稳定性和热降解行为对研究该材料的使用范围和成型加工…  相似文献   

3.
研究了结晶性高分子聚对苯二甲酸乙二酯(PET)聚二苯氧乙烷(1,2)二甲酸(P.P′)乙二酯(PEET)混合系的热结晶化机理.用DSC,X光,偏光显微镜观测研究发现,PET与PEET的熔融混合并未发生酯交换和共聚合等化学反应,各组分独立结晶,它们的结晶度、结晶速度、球晶结构受到结晶化温度和混合组成两因子的影响,提出了表征这种效果的综合结晶化阻碍因子值.  相似文献   

4.
不同拉伸比PET/PBT共混纤维的热行为及力学性能   总被引:1,自引:0,他引:1  
尹秀丽 《应用化学》1995,12(3):111-112
不同拉伸比PET/PBT共混纤维的热行为及力学性能尹秀丽(天津纺织工学院材料科学系天津300160)关键词聚对苯二甲酸乙二醇酯,聚对苯二甲酸丁二醇酯,共混纤维,热行为,力学性能不同配比聚对苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丁二醇酯(PBT)共混...  相似文献   

5.
聚对苯二甲酸乙二酯的非等温结晶行为   总被引:2,自引:0,他引:2  
用付里叶变换红外光谱法、示差扫描量热、广角X 射线衍射和密度法等手段,研究了聚对苯二甲酸乙二酯(PET)的非等温结晶行为.在110℃以上,PET的结晶度随温度的升高而增加;在160~230℃温度区间,PET的结晶度随温度的升高变化不大.但在其后的降温过程中,其结晶度显著增加.从高温缓冷试样的结晶度明显地比淬火试样的高.实验结果有力地支持了高聚物在结晶前链的折叠就已经形成的观点.  相似文献   

6.
本文研究工作表明,聚乙二醇(PEG)作为聚对苯二甲酸乙二酯(PET)/聚对苯二甲酸丁二酯(PBT)共混体系的结晶促进剂.不仅使聚合物分子链运动容易而有利于结晶时定向排列,晶体生成速度加快.而且使成核剂的成核效率提高,晶核生成速度加快,晶核数目增多而晶体尺寸减小.此外,PEG还部分参与了聚酯的酯交换反应,在低用量时有利于聚合物特性粘数提高,而用量增大则引起聚酯降解.由于PEG的这些作用,共混体系在PEG为6.0%时的模量及γ-衰减强度最大.动态力学性能最好.  相似文献   

7.
本文研究工作表明,聚乙二醇作为聚对苯二甲酸乙二酯(PET)/聚对苯二甲酸丁二酯(PBT)共混体系的结晶促进剂,不仅使聚合物分子链运动容易而有利于结晶时定向排列,晶体生成速度加快,而且使成核的成效率提高,晶核生成速度加快,晶核数目增多而晶体尺寸减小,此外,PEG还部分参与了聚酯的酯交换反应,在低用量时有利于聚合物特性粘数提高,而且量增大则引起聚酯降解。由于PEG的这些作用,共混体系在PEG为6.0%  相似文献   

8.
用DSC和溶剂诱导结晶(SINC)的方法对比研究了(GOLR)态和未取向聚对苯二甲酸乙二酯(PET)纤维样品的结晶行为.实验结果表明,样品的大尺度取向可有效地降低样品的冷结晶温度(Tcc),证明大尺度取向对样品的结晶行为可起到促进作用.  相似文献   

9.
通过密度法、DSC、力学性能测试等方法研究了物理老化对聚对苯二甲酸乙二酯(PET)纤维溶剂诱导结晶速率及结构的影响,并进一步探讨了取向程度对PET纤维物理老化过程的影响.发现在一定老化温度下,PET纤维的溶剂诱导结晶(SINC)速率随老化时间的延长呈现先降低后升高的趋势;取向程度高的样品则经较短的老化时间即可出现这种情况.对上述现象用凝聚缠结的观点加以解释.  相似文献   

10.
研究以通用高分子聚己内酰胺(PA-6)及聚对苯二甲酸乙二醇酯(PET)为基质材料,用连续气相聚合的方法,使聚吡咯与之复合,可得到聚吡咯/PA-6(PPy/PA-6)及聚吡咯/聚对苯二甲酸乙二醇酯(PPy/PET)导电复合纤维,电导率最高可达10-1S/cm,力学性能有所下降。  相似文献   

11.
The solubility behaviors of poly(sulfonyldiphenylene phenylphosphonate) (PSPPP), a very efficient flame retardant for poly(ethylene terephthalate) (PET), in more than 50 solvents were examined. Its solubility parameters (δ) were determined by the intrinsic viscosity and turbidic titration methods. The two methods obtained consistent results, δ = 21.0–21.6 J1/2/cm3/2 and δ = 21.0 J1/2/cm3/2, and the three‐dimensional solubility parameters were δd = 18.9 J1/2/cm3/2, δp = 8.8 J1/2/cm3/2, and δh = 5.9 J1/2/cm3/2. The miscibility of PSPPP with PET was estimated by the calculation of the heats of mixing, which were related to the difference between the solubility parameters of PSPPP and PET. Fourier transform infrared was used to examine the interactions between PSPPP and PET macromolecules, which were the internal factors of polymer–polymer miscibility. The results showed that PSPPP and PET were miscible within a very wide composition range, especially with less than 15 wt % PSPPP, a composition of interest for the preparation of flame‐retardant PET. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2296–2301, 2003  相似文献   

12.
The fire performance of polystyrene‐organic montmorillonite (OMMT) nanocomposite was investigated by limiting oxygen index (LOI) and cone calorimetry. Scanning electron microscopy, electron dispersive spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy were employed to study the charring process of the nanocomposite. The residue collected upon thermal degradation was analyzed by various means to determine its composition and to understand the flame‐retardant mechanism of the nanocomposite. It has been shown that the introduction of OMMT does not have much influence on LOI of the nanocomposite, but can greatly decrease the heat release rate (HRR) and mass loss rate (MLR) and enhance the flame retardancy of the material. The flame‐retardant mechanism is due to charring in the condensed phase. The intercalated nanostructure is destroyed, and the silicate nanolayers in the nanocomposite rearrange and accumulate on the material surface during pyrolysis. The charred residue has a honeycomb‐like porous structure, which covers on the material surface and serves as a protection barrier against heat transfer and mass exchange, leading to enhanced flame retardancy. The charred residue is composed of pyrolyzed silicate layers and graphitic char. The char is highly stable in nitrogen even at 800 °C, but thermo‐oxidative decomposition is allowed, and it can be removed completely in the presence of air. Due to the porous structure of the charred residue, the protection from it is mainly to reduce the HRR and MLR and retard burning of the material. It is not enough to make the nanocomposite self‐extinguish. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

13.
In order to compare their inherent flame retardancy and thermal stability, two phosphorus-containing thermotropic liquid crystalline copolyesters (P-TLCP) were synthesized by melting transesterification. Additionally based on the facts that the P-TLCP can work as a functional additive to enhance the flame retardancy and mechanical property of PET, we further studied the flame retardant mechanism. Scanning Electronic Microscope (SEM) observations show that the char from PET/P-TLCP is more compact, therefore more efficiently resists fire and heat attack than pure PET. Moreover, Fourier Transform Infrared Spectroscopy (FTIR) measurements of evolved gas, indicate that P-TLCP decomposes to produce phosphorus-containing small molecular compounds during the pyrolysis process, such that P-TLCP could play a flame retardant role in vapour phase. Furthermore, P-TLCP strongly inhibits the generation of combustible compounds in the pyrolysis of PET, which also helps to resist fire propagation.  相似文献   

14.
A phosphorus-nitrogen containing flame retardant additive of poly(phosphoric acid piperazine),defined as PPAP,was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid,and the dehydration polymerization under heating in nitrogen atmosphere.Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy,13C and 31p solid-state nuclear magnetic resonance measurements.The synthesized PPAP and curing agent m-phenylenediamine were blended into epoxy resin (EP) to prepare flame retardant EP thermosets.The effects of PPAP on the fire retardancy and thermal degradation behavior of cured EP/PPAP composites were investigated by limiting oxygen index (LOI),vertical burning (UL-94),thermogravimetric analysis/infrared spectrometry (TG-IR) and cone calorimeter tests.The morphologies and chemical compositions of char residues for cured epoxy resin were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS),respectively.The results demonstrated that the flame retardant EP thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 30.8% when incorporating 5wt% PPAP into the EP thermosets.The TGA results indicated that the synthesized PPAP flame retardant additive possessed high thermal stability and excellent charring capability.Meanwhile,the incorporation of PPAP stimulated the epoxy resin matrix to decompose and charring ahead of time due to its catalytic decomposition effect,which led to a higher char yield at high temperature.The morphological structures and the analysis results of XPS for char residues of EP thermosets revealed that the introduction of PPAP benefited the formation of a sufficient,more compact and homogeneous char layer containing phosphorus-nitrogen flame retardant elements on the material surface during combustion.The formed char layer with high quality effectively prevented the heat transmission and diffusion,limited the production of combustible gases,and inhibited the emission of smoke,leading to the reduction of heat and smoke release.  相似文献   

15.
采用原位聚合法制备了蜜胺树脂(MF)和环氧树脂(EP)双层包裹聚磷酸铵(APP),得到一种新型核壳结构的微胶囊阻燃剂(EMFAPP).用傅里叶红外光谱(FTIR)和扫描电镜(SEM)对微胶囊的核壳结构进行了表征;用极限氧指数(LOI)、垂直燃烧等级测试(UL 94)对EMFAPP在EP中的阻燃性能进行了研究.EMFAPP在EP基体中阻燃性能优异,当其添加量大于7%时EP/EMFAPP均通过UL 94 V-0级,LOI值达27.0%以上.与未包裹APP相比,EMFAPP耐水性明显提高;经水处理(75℃,6天)后,EMFAPP/EP仍可保持良好的阻燃性能.采用热重分析对EMFAPP及其阻燃复合物的热降解行为进行了研究,EMFAPP能够促进成炭,EP/EMFAPP(8 wt%)在700℃残炭率达16.2%,但其低温稳定性有所下降.此外,利用热失重-红外联用对EMFAPP/EP的热降解行为进行了研究,探讨相关阻燃机理.  相似文献   

16.
A novel phosphorus-containing compound, poly(2-hydroxy propylene spirocyclic pentaerythritol bisphosphonate) (PPPBP) has been proved to be an excellent flame retardant for polyethylene terephthalate (PET) fabrics. In order to understand its flame retardant mode, FT-IR and XPS are used to investigate the char-forming mechanism of PPPBP. FT-IR spectra results show that with the increase of temperature, P-O-C group of PPPBP breaks down gradually, and species containing CC double bond appear. XPS spectra indicate that PPPBP produces phosphoric or polyphosphoric acid during thermo-decomposition. In the high temperature range (>400 °C), CC and phosphorus-containing complexes become the major components of the charred residue of PPPBP. Data of XPS and FT-IR spectra give positive evidence that PPPBP yields high amount of carbonaceous chars by producing phosphoric or polyphosphoric acid, which inhibit the oxidation of carbon atoms, and simultaneously impel the formation of carbon and species containing carbon double bond with outstanding heat resistance.  相似文献   

17.
The flammability characteristics and flame retardant mechanism of phosphate-intercalated hydrotalcite (MgAl-PO4) in the halogen-free flame retardant ethylene vinyl acetate (EVA) blends have been studied by X-ray diffraction (XRD), Fourier transfer infrared (FTIR) spectroscopy, cone calorimeter test (CCT), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), limiting oxygen index (LOI) and UL-94 tests. The results show that the hydrotalcite MgAl-PO4 intercalated by phosphate possesses the enhanced thermal stability and flame retardant properties compared with ordinary carbonate-intercalated hydrotalcite MgAl-CO3 in the EVA blends. The CCT tests indicate that the heat release rate (HRR) and mass loss rate (MLR) values of the EVA/MgAl-PO4 samples are much lower than those of the EVA/MgAl-CO3 samples. The TGA data show that the thermal degradation rates of MgAl-PO4 and EVA/MgAl-PO4 samples are much slower and leave more charred residues than those of MgAl-CO3 and its corresponding EVA blends. The LOI values of EVA/MgAl-PO4 samples are 2% higher than those of the corresponding EVA/MgAl-CO3 samples at the range of 40–60 wt% loadings, while the EVA sample with 55 wt% MgAl-PO4 can reach the UL-94 V-1 rating. The dynamic FTIR spectra reveal that the flame retardant mechanism of MgAl-PO4 can be ascribed to its catalysis degradation of the EVA resin, which promotes the formation of charred layers with the P–O–P and P–O–C complexes in the condensed phase. The SEM observations give further evidence of this mechanism that the compact charred layers formed from the EVA/MgAl-PO4 sample effectively protect the underlying polymer from burning.  相似文献   

18.
《先进技术聚合物》2018,29(1):668-676
A phosphorous‐nitrogen intumescent flame‐retardant, 2,2‐diethyl‐1,3‐propanediol phosphoryl melamine (DPPM), was synthesized and characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Flame‐retardant rigid polyurethane foams (RPUFs) with DPPM (DPPM‐RPUF) as fire‐retardant additive were prepared. Scanning electron microscope (SEM) and mechanical performance testing showed that DPPM exhibited a favorable compatibility with RPUF and negligibly negative influence on the mechanical properties of RPUF. The flame retardancy of DPPM on RPUF was investigated by the limiting oxygen index (LOI), vertical burning test and cone calorimeter. The LOI of DPPM‐RPUF could reach 29.5%, and a UL‐94 V‐0 rating was achieved, when the content of DPPM was 25 php. Furthermore, the DPPM‐RPUF exhibited an outstanding water resistance that it could still obtain a V‐0 rating after water soaking. Thermogravimetric analysis showed that the residual weight of RPUF was relatively low, while the charring ability of DPPM‐RPUF was improved greatly. Real‐time Fourier transform infrared spectroscopy was employed to study the thermo‐oxidative degradation reactions of DPPM‐RPUF. The results revealed that the flame‐retardancy mechanism of DPPM in RPUF was based on the surface charred layer acting as a physical barrier, which slowed down the decomposition of RPUF and prevented the heat and mass transfer between the gas and the condensed phases.  相似文献   

19.
The main aim of this work was to investigate the synergistic effect of expandable graphite (EG) and aluminum hypophosphite (AHP) on the flame retardancy of rigid polyurethane foams (RPUFs). A series of flame retardant RPUF containing EG and AHP were prepared by one‐shot and free‐rise method. The flame retardant, thermal degradation, and combustion properties of RPUF hybrids were characterized through limiting oxygen index (LOI) test, vertical burning (UL‐94) test, thermogravimetric analysis and microscale combustion calorimeter. The LOI and UL‐94 results showed that the RPUF sample with 10 wt% EG and 5 wt% AHP passed UL‐94 V‐0 rating and reached a relatively high LOI value of 28.5%, which is superior over other EG/AHP ratios in RPUF at the equivalent filler loading. Microscale combustion calorimeter results revealed that the incorporation of EG and AHP into RPUF reduced the peak heat release rate and total heat release, thus decrease the fire risk of RPUF significantly. Incorporation of EG and AHP improved the thermal stability of RPUF as observed from the thermogravimetric analysis results and also enhanced the thermal resistance of char layer at high temperature from scanning electron microscopy and Raman spectroscopy. Moreover, it could be seen from thermogravimetric analysis/infrared spectrometry spectra that the addition of EG and AHP significantly decreased the combustible gaseous products such as hydrocarbons and ethers. Finally, the synergistic mechanism in flame retardancy was discussed and speculated. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

20.
Halogen free nitrogen-phosphorous flame retardants (PMOP) were prepared through reaction of melamine and polyphosphoric acid in the presence of flame retardant modifier CM with silicotungistic acid as a catalyst in aqueous solution. FT-IR, XRD, DSC and TGA techniques were used to characterize the reaction product PMOP. The obtained flame retardants were then used to prepare flame retardant (FR) polyamide 6 (PA6) composite reinforced with glass fiber (GF) and the factors affecting the flame retardancy of the material were also investigated. The FR GF reinforced PA6 composite and the obtained charred layers were analyzed by utilizing TGA, SEM, FT-IR and XRD. The properties of the charred layer were connected with the flame retardancy of the corresponding material to reveal the flame retarding mechanism of FR GF reinforced PA6 composite. The experimental results show that PMOP flame retardant consists of melamine polyphosphate, melamine phosphate and possible melamine pyrophosphate. The presence of CM was found to improve the flame retardancy of FR GF reinforced PA6 composite. It was experimentally found that PMOP flame retardant, which is comparatively stable in the range of processing temperatures of PA6, is particularly suitable for flame retarding PA6 reinforced with GF. With increasing the flame retardant content, the flame retardancy of the FR reinforced material is not improved so obviously. However, the increase in the GF content greatly improves the flame retardancy of the composite, because GF greatly increases the char yield of material, decreases the maximal thermal decomposition rate, promotes the formation of charred layer with (PNO)x structure and greatly increases the strength of the charred layer. The prepared FR GF reinforced PA6 composites have good comprehensive properties with flame retardancy 1.6 mm UL 94 V-0 level, tensile strength 76.8 MPa, Young's modulus 11.7 GPa, Izod notched impact strength 4.5 kJ/m2, flexural strength 98.0 MPa and flexural modulus 7.2 GPa, showing a better application prospect.  相似文献   

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