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1.
Mg–Al–Fe ternary layered double hydroxides (LDH) were synthesized based on bayer red mud by calcination‐rehydration method, and characterized using X‐ray diffraction and thermogravimetric analysis (TGA). The synergistic flame retardant effects of ammonium polyphosphate (APP) with LDH in ethylene‐vinyl acetate (EVA) composites were studied using limiting oxygen index (LOI), UL 94 test, cone calorimeter test (CCT), and smoke density test (SDT). The thermal degradation behavior of EVA/LDH/APP composites was examined by thermal gravimetric analysis‐fourier transform infrared spectrometry (TG‐FTIR). The results showed that LOI values decreased by incorporation of APP together with LDH; and, a suitable amount of APP in EVA/LDH composites can apparently improve UL 94 rating. The CCT results indicated that heat release rate (HRR) of the EVA/LDH/APP composites with APP decreased in comparison with that of the EVA/LDH composites. The SDT results showed that APP was helpful to suppress smoke. The TG‐FTIR data showed that the composites with APP had a higher thermal stability than the EVA/LDH composites at high temperature. POLYM. ENG. SCI., 54:766–776, 2014. © 2013 Society of Plastics Engineers  相似文献   

2.
Mg–Al–Fe ternary hydrotalcites were synthesized by a coprecipitation method and characterized with powder X‐ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The flame‐retardant effects of Mg/Al–CO3 layered double hydroxides (LDHs) and Mg/Al/Fe–CO3 LDHs in an ethylene/vinyl acetate copolymer (EVA) were studied with the limited oxygen index (LOI), the UL‐94 test, and the cone calorimeter test (CCT), and the thermal degradation behavior of the composites was examined by thermogravimetric analysis. The results showed that the LOI values of the EVA/(Mg/Al/Fe–CO3 LDH) composites were basically higher than those of the EVA/(Mg/Al–CO3 LDH) composites at the same additive level. In the UL‐94 test, there was no rating for the EVA/(Mg/Al–CO3 LDH) composite at the 50% additive level, and a dripping phenomenon occurred. However, the EVA/(Mg/Al/Fe–CO3 LDH) composites at the same loading level of LDHs containing a suitable amount of Fe3+ ion reached the V‐0 rating, the dripping phenomenon disappearing. The CCTs indicated that the heat release rate (HRR) of the EVA composites with Mg/Al/Fe–CO3 LDHs containing a suitable amount of Fe3+ decreased greatly in comparison with that of the composites with Mg/Al–CO3 LDHs. The introduction of a given amount of Fe3+ ion into Mg/Al–CO3 LDHs resulted in an increase in the LOI, a decrease in the HRR, and the achievement of the UL‐94 V‐0 rating. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

3.
In this work, the flammability behaviors and synergistic effects of red phosphorus masterbatch (RPM) with expandable graphite (EG) in flame‐retardant high‐density polyethylene/ethylene vinyl‐acetate copolymer (HDPE/EVA) composites have been investigated by limiting oxygen index (LOI), UL‐94 test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), Fourier‐transform infrared (FTIR) and scanning electron microscopy (SEM). The data obtained from LOI, UL‐94 test and CCT showed that suitable amount of RPM had synergistic effects with EG in the HDPE/EVA/EG/RPM composites. The addition of RPM greatly increased the LOI values by 3.4%, obtained UL‐94 V‐0 rating, decreased the heat release rates and total heat release, and prolongated the ignition time when 6.7 phr RPM substituted for EG in the HDPE/EVA/EG/RPM composites. The data from TGA and FTIR spectra also indicated the synergistic effects of RPM with EG considerably enhanced the thermal degradation temperatures. The morphological observations after UL‐94, CCT, and SEM images presented positive evidences that the synergistic effects took place for RPM with EG, and the flame‐retardant mechanism has been changed in flame‐retardant HDPE/EVA/EG/RPM composites. The formation of stable and compact charred residues promoted by RPM acted as effective heat barriers and thermal insulations, which improved the flame‐retardant performances and prevented the underlying polymer materials from burning. POLYM. ENG. SCI., 55:2884–2892, 2015. © 2015 Society of Plastics Engineers  相似文献   

4.
Abstract

The synergistic effects of Fe organic modified montmorillonite (Fe-OMMT) with layered double hydroxides (LDHs) in ethylene vinyl acetate copolymer/LDH (EVA/LDH) composites have been studied using thermal analysis [thermogravimetric analysis (TGA)], limiting oxygen index (LOI), UL-94 test and cone calorimeter test (CCT). The results showed that the addition of a given amount of Fe-OMMT apparently increased the LOI value and the rating in the UL-94 test. The results from the LOI and UL-94 tests show that Fe-OMMT can act as flame retardant synergistic agents in EVA/LDH composites. The CCT data indicated that the addition of Fe-OMMT in the EVA/LDH system can greatly reduce the heat release rate. The TGA data show that Fe-OMMT, as an excellent flame retardant synergist of LDH, cannot increase the thermal degradation temperature and the charred residues.  相似文献   

5.
With a melamine-formaldehyde (MF) resin coating layer, microencapsulated ammonium polyphosphate (MCAPP) is prepared by in situ polymerization and is characterized by XPS and water leaching test. The microencapsulation of APP with the MF resin leads to a decrease in the particle's water leaching rate. The flame-retardant action of MCAPP and APP in EVA are studied using LOI and UL 94 test, and their thermal stability is evaluated by thermogravimetric analysis (TGA). The LOI value of the EVA/MCAPP composite at the same loading is higher than the value of the EVA/APP composite. In comparison with the EVA/MCAPP composites, it is found that the LOI values of the EVA/MCAPP/PER and EVA/MCAPP/DPER ternary composites at the same additive loading increase, and UL 94 ratings of most ternary composites are raised to V-0. The water-resistant properties of the EVA composites are studied, and the results of the composites containing with APP and MCAPP are compared. Moreover, the peroxide cross-linking of the EVA composites is investigated, and the mechanical properties and thermal stability of the composites increase after the cross-linking.  相似文献   

6.
采用共混法在乙稀醋酸乙烯共聚物/丁腈橡胶(EVA/NBR)复合材料中加入钼酸铵(AHM),通过烟密度测试、燃烧行为测试及热重分析研究了钼酸铵对复合体系的燃烧性能、抑烟性及热稳定性的影响。结果表明,添加1.0份(质量份,下同)AHM的复合材料的最大烟密度值降低到59.5 %,且烟密度等级仅为34.7,极限氧指数可达到33.3 %,UL 94垂直燃烧等级达到V-0级别,且燃烧时最大热释放速率从302 kW/m2降低到241 kW/m2;加入AHM后,复合材料的热稳定性提高;加入AHM后,烟密度实验后的残炭表面形貌更加致密。  相似文献   

7.
The synergistic effects of 4A zeolite (4A) on the thermal degradation, flame retardancy, and char formation of an efficient halogen‐free flame‐retardant ethylene‐vinyl acetate copolymer composite (EVA/IFR) were investigated by limited oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter test (CCT), digital photography, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), laser Raman spectroscopy (LRS) and thermogravimetric analytical (TGA) methods. It was found that a small amount of 4A clearly improved the LOI value of the EVA/IFR composite and reinforced the fire retardant performance with a great reduction in the combustion parameters of the EVA/IFR system from the CCT test. The entire composites passed the UL‐94 V‐0 rating test. The TGA and integral procedure decomposition temperature (IDPT) results showed that 4A enhanced the thermal stability of the EVA/IFR system and increased the char residue content effectively. The morphological structures observed by digital and SEM imaging revealed that 4A could promote EVA/IFR to form a more continuous and compact intumescent char layer. The LRS and EDS results demonstrated that by introduction of 4A into the EVA/IFR system, a more graphite structure was formed with increase phosphorus content in the char residue. POLYM. ENG. SCI., 56:380–387, 2016. © 2016 Society of Plastics Engineers  相似文献   

8.
A synergistic effect on flame retardancy was found when hydroxy silicone oil (HSO) was incorporated into ethylene vinyl acetate/aluminum hydroxide (EVA/ATH) composite. The fire performance of EVA and EVA composites was studied by using limiting oxygen index (LOI), UL 94, and cone calorimeter test (CCT). Compared with the EVA/ATH binary composite, the LOI values of the EVA/ATH/HSO ternary composites at the same additive loading are all decreased. The CCT data indicated that the addition of HSO in EVA/ATH system not only reduces the heat release rate, but also prolonged the ignition time of the composite. Thermogravimetric analysis revealed that ATH accelerated the loss of acetic acid, but hydroxy silicone oil assisted to reduce ATH's accelerating effect.  相似文献   

9.
A novel charring agent (CNCA‐DA) containing triazine and benzene ring, using cyanuric chloride, aniline, and ethylenediamine as raw materials, was synthesized and characterized. The effects of CNCA‐DA on flame retardancy, thermal degradation, and flammability properties of polypropylene (PP) were investigated by limited oxygen index (LOI), vertical burning test (UL‐94), thermogravimetric analysis (TGA), and cone calorimeter test (CCT). The TGA results showed that CNCA‐DA had a good char forming ability, and a high initial temperature of thermal degradation; the char residue of CNCA‐DA reached 18.5% at 800°C; Ammonium polyphosphate (APP) could improve the char residue of APP/CNCA‐DA system, the char residue reached 31.6% at 800°C. The results from LOI and UL‐94 showed that the intumescent flame retardant (IFR) containing CNCA‐DA and APP was very effective in flame retardancy of PP. When the mass ratio of APP and CNCA‐DA was 2 : 1, and the IFR loading was 30%, the IFR showed the best effect; the LOI value reached 35.6%. It was also found that when the IFR loading was only 20%, the flame retardancy of PP/IFR can still pass V‐0 rating in UL‐94 tests, and its LOI value reached 27.1%. The CCT results demonstrated that IFR could clearly change the decomposition behavior of PP and form a char layer on the surface of the composites, consequently resulting in efficient reduction of the flammability parameters, such as heat release rate (HRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSP), and mass loss (ML). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

10.
A kind of intumescent ?ame-retardant curing agent (PCDSPB) was synthesised by using pentaerythritol, phosphorus oxycholoride, cyclohexane-1,3-diyldimethanamine (1,3- BAC) as raw materials and the structure was characterised by FTIR and MS. The composite materials were investigated by using TG, TG-FTIR, LOI, UL-94, SEM, and CCT. The results show that the ?lling of PCDSPB can improve the ?ame resistance of EP composites. When the phosphorus content of the composite system was 1.74 wt-%, the initial weight loss temperature was 299°C and the char yield was 26.3% at 600°C. Tensile strength was 35.4 MPa, impact strength was4.3 kJ m?2, LOI was 27.9, and the UL94 passed V-0 level. In the CCT, the peak heat release rate reduced to 276.0 kW m?2(EP-2) from 622.8 kW m?2 (EP-0), the total heat release decreased from 121.8 MJ m?2 (EP-0) to 89.5 MJ m?2 (EP-2). Therefore, the PCDSPB is a good intumescent ?ame-retardant curing agent for EP.  相似文献   

11.
The flammable, thermal, and mechanical properties of intumescent flame retardant (IFR) polypropylene/layered double hydroxide (PP/IFR/LDH) nanocomposites with the LDHs of different divalent cations and IFR system of ammonium polyphosphate/pentaerythritol (APP/PER) have been studied by X-ray diffraction (XRD), cone calorimeter test (CCT), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), limiting oxygen index (LOI), UL-94 test, and mechanical measurements. The XRD results show that the exfoliated PP/IFR/LDH nanocomposites possess the nanoscaled dispersion characteristic. The data from the CCT tests show the synergistic effect of LDHs with IFR can decrease considerably the HRR, MLR, and EHC values of the PP/IFR/LDH nanocomposites, in which the pk-HRR, pk-MLR, and pk-EHC values of the PP/IFR/ZnAl-LDH sample decrease to 318 kW/m2, 0.081 g/m2 s, 61.8 MJ/kg from the corresponding values 506 kW/m2, 0.115 g/m2 s, 71.8 MJ/kg of the PP/IFR sample. The LOI and UL-94 data further support the evidence that the flame retardant synergistic effects of LDHs with IFR increase the LOI values and UL-94 rating, especially for the LDHs with the transition ions (Zn, Cu) the LOI values can reach 33% and the UL-94 pass the V-0 rating. The TGA results demonstrate the LDHs can greatly improve the thermal stabilities of PP/IFR/LDH nanocomposites by increasing the thermo-oxidation decomposition temperature and charred residues. The morphological structures observed by SEM have demonstrated the LDHs can promote formation of compact charred layers. The data from the mechanical tests show the tensile strength and elongation at break of the PP/IFR/LDH samples are basically unchanged compared with the PP/IFR sample. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers  相似文献   

12.
Pentaerythritol phosphate melamine salt (PPMS) as a single‐molecule intumescent fire retardant was synthesized and characterized. The influence of the PPMS content on the combustion and thermal decomposition processes of intumescent‐flame‐retardant (IFR) ethylene–vinyl acetate copolymer (EVA) composites was studied by limiting oxygen index (LOI) measurement, UL 94 rating testing, cone calorimetry, thermogravimetric analysis, and scanning electron microscopy. The LOI and UL 94 rating results illustrate that PPMS used in EVA improved the flame retardancy of the EVA composites. The cone calorimetry test results show that the addition of PPMS significantly decreased the heat‐release rate, total heat release, and smoke‐production rate and enhanced the residual char fire performance of the EVA composites. The IFR–EVA3 composite showed the lowest heat‐release and smoke‐production rates and the highest char residue; this means that the IFR–EVA3 composite had the best flame retardancy. The thermogravimetry results show that the IFR–EVA composites had more residual char than pure EVA; the char residue yield increased with increasing PPMS content. The analysis results for the char residue structures also illustrated that the addition of PPMS into the EVA resin helped to enhance the fire properties of the char layer and improve the flame retardancy of the EVA composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42148.  相似文献   

13.
A novel bio-based carbon forming agent (Mg@PA-CS) containing P and N elements was were synthesized using the complexation characteristics of chitosan (CS) and phytate (PA). The flame retardant behavior of poly(lactic acid) (PLA)/Mg@PA-CS/APP composites (addition of 20 wt% of different ratios of Mg@PA-CS and APP to polylactic acid composites) were investigated by the limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetry test (CCT), and thermogravimetric analysis (TGA). Due to the biphasic flame retardant and synergistic effect, since the 20 wt% flame retardant system (Mg@PA-CS:APP = 1:2), PLA composites passed the UL-94 test V-0 rating, reached 34% LOI value. The peak heat release rate (PHRR) and total heat release rate (THR) were reduced to 1/2 of the pure PLA, char residue could be as high as 11.49% at 800°C. Moreover, the flame-retardant mechanism of PLA composites during thermal decomposition was analyzed using a scanning electron microscope (SEM) and the coupling techniques of TGA linked with FT-IR (TG-FTIR).  相似文献   

14.
Ammonium polyphosphate (APP)–polystyrene (PSt) core–shell microspheres (CSPs) were synthesized via in situ radical polymerization. The core–shell structure was confirmed by transmission electron microscope (TEM). The results of optical contact angle measurements demonstrated a significant improvement in hydrophobicity of the modified APP. The obtained APP–PSt CSPs were added into epoxy (EP) system with various loadings. Effects of CSP on flame retardancy, thermal properties, heat release rate (HRR), smoke production, and mechanical properties of EP/CSP composites were investigated by limiting oxygen index (LOI), UL‐94 tests, thermogravimetric analysis (TGA), cone calorimeter, and tensile test. LOI and UL‐94 indicated that CSP remarkably improved the flame retardancy of EP composites. TGA showed that the initial decomposition temperature and the maximum‐rate decomposition temperature decreased, whereas residue yields at high temperature increased with the incorporation of microspheres. Cone calorimetry gave evidence that HRR, peak release rate, average HRR, and smoke production rate of EP/CSP composites decreased significantly. The morphology of char residues suggested that CSP could effectively promote EP to form high‐quality char layer with compact outer surface and swollen inner structure. Tensile strength of EP was enhanced with the addition of CSP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40218.  相似文献   

15.
The composites based on ethylene–propylene–diene monomer rubber (EPDM) with aluminum hydroxide (ATH), nanoclay, vulcanizing agent, and curing accelerator were prepared by conventional mill compounding method. The thermal stability and the flame retardant properties were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 test, cone calorimeter, and smoke density chamber tests. The results indicated that the substitution of the nanoclay in the EPDM/ATH composites increased the 50% weight loss temperature and the LOI value, and reduced the peak heat release rate (pk‐HRR), the extinction coefficient (Ext Coef), the maximal smoke density (Dm), and the whole smoke at the first 4 min (VOF4) of the test specimens. The synergistic flame retardancy of the nanoclay with ATH in EPDM matrix could imply that the formation of a reinforced char/nanoclay layer during combustion prevents the diffusion of the oxygen and the decomposed organic volatiles in the flame. The mechanical properties of the composites have been increased by replacing more of the nanoclays into the EPDM/ATH blends. The best loading of the nanoclay in EPDM/ATH composites is 3 wt %, which keeps LOI in the enough value, the V‐0 rating in the UL‐94 test, and the improved mechanical properties with better dispersion and exfoliation of the nanoclays shown by transmission electron microscopy (TEM) micrographs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2042–2048, 2013  相似文献   

16.
采用氧化铝(Al2O3)为导热填料、氢氧化镁[Mg(OH)2]为阻燃填料,以低密度聚乙烯(PE-LD)和乙烯醋酸乙烯共聚物(EVA)为基体树脂制备导热阻燃复合材料。通过导热性能测试、燃烧行为表征(极限氧指数和垂直燃烧测试)以及热重分析研究了PE LD/EVA/Al2O3/Mg(OH)2复合材料的导热性能、阻燃性能及热稳定性。结果表明,含有50份Al2O3及50份Mg(OH)2的复合材料,在PE-LD/EVA质量比为1/1时,热导率可达到1.21 W/m·K;材料的阻燃性能及热稳定性都随 EVA 含量的增加而增大,极限氧指数从27.0 % 提高到31.5 %,UL 94 垂直燃烧从无等级提高到V-0级,残炭率从46.5 %提高到57.7 %。  相似文献   

17.
将BaCl2分级的k型卡拉胶(KC)和纳米氢氧化铝〔Al(OH)3〕构成的协同阻燃体系添加到天然橡胶(NR)中制备KC-Al(OH)3/NR复合材料。通过TG、极限氧指数(LOI)、锥形量热(CCT)以及SEM考察了不同质量比的KC和Al(OH)3对复合材料力学性能和阻燃性能的影响。结果表明,当KC与Al(OH)3以1∶1的质量比加入到NR时,KC-Al(OH)3/NR复合材料的热稳定性、阻燃性能最优,复合材料的LOI达到25%。与纯天然橡胶相比,复合材料总热释放量(THR)、热释放速率峰值(pHRR)、总烟释放量(TSP)和平均质量损失率(AMLR)分别降低了12%、65%、23%和62%。相比于单独添加Al(OH)3体系,复合材料拉伸强度和断裂伸长率分别增加了11%和17%。  相似文献   

18.
A new intumescent flame retardant (IFR) system consisting of ammonium polyphosphate (APP) and charing‐foaming agent (CFA) and a little organic montmorillonite (OMMT) was used in low‐density polyethylene (LLDPE)/ethylene‐vinyl acetate (EVA) composite. According to limiting oxygen index (LOI) value and UL‐94 rating obtained from this work, the reasonable mass ratio of APP to CFA was 3 : 1, and OMMT could obviously enhance the flame retardancy of the composites. Cone calorimeter (CONE) and thermogravimetric analysis (TGA) were applied to evaluate the burning behavior and thermal stability of IFR‐LLDPE/EVA (LLDPE/EVA) composites. The results of cone calorimeter showed that heat release rate peak (HRR‐peak) and smoke production rate peak (SPR‐peak) and time to ignition (TTI) of IFR‐LLDPE/EVA composites decreased clearly compared with the pure blend. TGA data showed that IFR could enhance the thermal stability of the composites at high temperature and effectively increase the char residue. The morphological structures of the composites observed by scanning electron microscopy (SEM) and X‐ray diffraction (XRD) demonstrated that OMMT could well disperse in the composites without exfoliation, and obviously improve the compatibility of components of IFR in LLDPE/EVA blend. The morphological structures of char layer obtained from Cone indicated that OMMT make the char layer structure be more homogenous and more stable. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

19.
The synergistic effects of fumed silica on the thermal and flame‐retardant properties of intumescent flame retardant (IFR) polypropylene based on the NP phosphorus‐nitrogen compound have been studied by 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 LOI and UL‐94 data show that when ≤1 wt % fumed silica substituted for the IFR additive NP can increase 2 to 4% LOI values of the PP blends and keep the V‐0 rating. The data obtained from the CCT tests indicate the heat release rates (HRR) reduce by about 23% for the PP/NP sample with 0.5 wt % fumed silica, whereas the mass loss rates (MLR) and total heat release (THR) values are much lower than those of the PP/NP samples without fume silica. The TGA data demonstrate that a suitable amount of fumed silica can increase the thermal stability and charred residue of the PP/IFR/SiO2 blends after 500°C. The morphological structures of charred residues observed by SEM give positive evidence that a suitable amount of fumed silica can promote the formation of compact intumescent charred layers and prevent the charred layers from cracking, which effectively protects the underlying polymer from burning. The dynamic FTIR spectra reveal that the synergistic flame‐retardant mechanism of a suitable amount of fumed silica with IFR additive is due to its physical process in the condensed phases. However, a high loading of fumed silica restricts the formation of charred layers with P? O? P and P? O? C complexes formed from burning of polymer materials and destroys the swelling behavior of intumescent charred layers, which deteriorates the flame retardant and thermal properties of the PP/IFR blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

20.
徐晓光 《中国塑料》2012,26(8):60-63
以聚磷酸铵(APP)和季戊四醇(PER)为膨胀型阻燃剂(IFR)制备了含有蒙脱土的无卤阻燃乙烯 醋酸乙烯共聚物(EVA)复合材料。通过极限氧指数、热失重分析、锥形量热分析等手段研究了有机蒙脱土(OMMT)的存在对EVA阻燃性能和热降解性能的影响,并通过扫描电子显微镜对复合材料残炭表面形貌进行了观察和分析。结果表明,加入有机蒙脱土可以促进复合材料成炭、改善炭层质量,从而起到了良好的隔热、抑烟作用;OMMT的最佳添加量为3份(质量份数,下同),复合材料的极限氧指数可达到29.4 %,垂直燃烧可达V 0级。  相似文献   

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