A new triazine polymer was synthesized by using cyanuric chloride, ethanolamine and ethylenediamine as raw materials. It is used both as a charring agent and as a foaming agent in intumescent flame retardants, designated as charring-foaming agent (CFA). Effect of CFA on flame retardancy, thermal degradation and mechanical properties of intumescent flame retardant polypropylene (PP) system (IFR-PP system) has been investigated. The results demonstrated that the intumescent flame retardant (IFR) consisting of CFA, APP and Zeolite 4A is very effective in flame retardancy of PP. It was found that when the weight ratio of CFA to APP is 1:2, that is, the components of the IFR are 64 wt% APP, 32 wt% CFA and 4 wt% Zeolite 4A, the IFR presents the most effective flame retardancy in PP systems. LOI value of IFR-PP reaches 37.0, when the IFR loading is 25 wt% in PP. It was also found that when the IFR loading is only 18 wt% in PP, the flame retardancy of IFR-PP can still pass V-0 rating, and its LOI value reaches 30.2. TGA data obtained in pure nitrogen demonstrated that CFA has a good ability of char formation itself, and CFA shows a high initial temperature of the thermal degradation. The char residue of CFA can reach 35.7 wt% at 700 °C. APP could effectively promote the char formation of the APP-CFA system. The char residue reaches 39.7 wt% at 700 °C, while it is 19.5% based on calculation. The IFR can change the thermal degradation behaviour of PP, enhance Tmax of the decomposition peak of PP, and promote PP to form char, based upon the results of the calculation and the experiment. This is attributed to the fact that endothermic reactions took place in IFR charring process and the char layer formed by IFR prevented heat from transferring into inside of IFR-PP system. TGA results further explained the effective flame retardancy of the IFR containing CFA. 相似文献
Novel intumescent flame retardant polypropylene (PP) composites were prepared based on a char forming agent (CFA) and silica-gel microencapsulated ammonium polyphosphate (Si-MCAPP). The thermal and flame retardancy of flame retardant PP composites were investigated by limiting oxygen index, UL-94 test, cone calorimetry, thermogravimetric analysis, scanning electron micrograph, and water resistance test. The results of cone calorimetry show that the flame retardant properties of PP with 30 wt% novel intumescent flame retardants (CFA/Si-MCAPP = 1:3) improve greatly. The peak heat release rate and total heat release decrease, respectively, from 1,140.0 to 156.8 kW m?2 and from 96.0 to 29.5 MJ m?2. The PP composite with CFA/Si-MCAPP = 1:3 has the excellent water resistance, and it can still obtain a UL-94 V-0 rating after 168 h soaking in water. 相似文献
A laboratory-made poly-N,N′-ethyleneterephthalamide (PETA) was used as a novel charring agent and it was combined with ammonium polyphosphate (APP) to prepare the intumescent flame retardant (IFR). For improving the flame retardant efficiency of IFR on acrylonitrile–butadiene–styrene copolymer (ABS), several adjuvant (Adj), such as zeolite 4A (4A), aluminum phosphinate (AlPi), organic montmorillonite, and 2,2′-bis(2-oxazoline), was added, and the synergistic effect was investigated by the limiting oxygen index (LOI), the UL-94 (vertical flame) test, the thermogravimetric analysis (TG), and the scanning electron microscopy (SEM). The results showed that the LOI values of ABS/IFR/Adj (70/30/2) system exceeded 30, and they passed the V-0 rating in the UL-94 test. The TG data demonstrated that the thermal stability and the mass residue of ABS/IFR/Adj were effectively enhanced. Besides, the SEM indicated that adjuvant promoted the formation of the compact, uniform, dense, and intumescent charred layer after burning. After that, the synergistic effect of AlPi and 4A on APP/PETA was investigated by Thermogravimetry-Fourier transform infrared spectroscopy. 相似文献
The effects of lanthanum oxide (La2O3) as a synergistic agent on the flame retardancy of intumescent flame retardant polypropylene composites (IFR-PP) were studied, and the new IFR system mainly consisted of the charring-foaming agent (CFA) and ammonium polyphosphate (APP). The limiting oxygen index (LOI), UL-94 test, thermogravimetric analysis (TGA), cone calorimeter (CONE) and scanning electron microscopy (SEM) were used to evaluate the synergistic effects of La2O3. It was found that when IFR was fixed at 20 wt% in IFR-PP composites, only a little amount of La2O3 could enhance LOI value and pass the UL-94 V0 rating test (1.6 mm). The TGA data showed that La2O3 could enhance the thermal stability of the IFR-PP systems at high temperature and effectively increase the char residue formation. The CONE results revealed that La2O3 and 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), ignition time (IT) and so on. The morphological structures observed by SEM demonstrated that La2O3 could promote to form the homogenous and compact intumescent char layer. Thus, a suitable amount of La2O3 plays a synergistic effect in the flame retardancy and smoke suppression of IFR composites. 相似文献
A novel phosphorus-containing triazine oligomer poly(2-morpholinyl-4-penta-erythritol phosphate-1,3,5-triazine) (PMPT) was synthesized as a kind of tri-component intumescent flame retardant (IFR). The chemical structure of PMPT was characterized by FTIR, 1H-NMR and 31P-NMR, and the mechanical and flammability properties of FR-PP were measured. The FTIR results showed that the expected chemical reactions had happened at each step. The 1H-NMR and 31P-NMR spectra also agreed with the chemical structure of PMPT. The slight effect of PMPT on the mechanical properties of FR-PP suggested that PMPT and PP are compatible. The high limited oxygen index (LOI) values of FR-PP revealed that PMPT was an efficient IFR and there was the synergistic effect between PMPT and ammonium polyphosphate/ pentaerythritol (APP/PER). 相似文献
This work aims to evaluate the efficiency of halloysite as synergistic agent in an intumescent PP system based on a coated ammonium polyphosphate (IFR). The first part of the study analyses the thermal stability and fire performance of PP when using the intumescent formulation alone or in combination with the aluminosilicate nanotubes (HNTs). Cone calorimetry reveals that partial substitution of IFR by HNTs (3 wt.%) imparts substantial improvement in flame retardancy with reduced heat release rate and longer burning times. Additionally, a shift from V-1 to V-0 classification is achieved at the UL-94 test with only 1.5 wt.% HNTs. The second part provides a better understanding of the physical and chemical mechanisms of action of HNTs in the intumescent systems. The chemical evolution of the condensed phase during combustion is described by solid state NMR, and in particular using 2D NMR. Results indicate that halloysite speeds up the development of the intumescent shield, but also enhances its mechanical properties by physical reinforcement (i.e. aluminosilicate “skeleton-frame” for the phospho-carbonaceous structure) and/or by chemical interactions with IFR yielding to aluminophosphates. These new chemical species allow thermal stabilization of the char at high temperatures and provide good macro- and micro-structural properties. Both effects increase the mechanical strength of the protective layer during burning ensuring excellent heat and mass transfer limitations between gas and condensed phases. 相似文献
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. 相似文献
In order to explore the structure mode of intumescent flame retardants (IFRs) with higher efficiency, IFR particles with joint‐aggregation structure (@IFR) were obtained through the treatment of ammonium polyphosphate (APP) and a charring agent (PT‐Cluster) in their aqueous solution. Then, the joint‐aggregation IFR effect was researched using its application in polypropylene. In case of 20 wt% IFR loading, the limiting oxygen index (LOI) value of @IFR/PP was 1.1% higher than that of 15APP/5PT‐Cluster/PP mixture, and a 1.6 mm‐thick @IFR/PP composite passed the UL 94 V‐2 rating test, while 15APP/5PT‐Cluster/PP demonstrated no flame‐retardant rating in UL 94 vertical burning tests. In a cone calorimeter test, @IFR also had a better inhibition effect on heat release. The average heat release rate (av‐HRR) value during 0 to 120 seconds of @IFR/PP was only 41 kW m?2, which was 33.9% lower than that of the 15APP/5PT‐Cluster/PP. Furthermore, the peak heat release rate (pk‐HRR) of @IFR/PP was 20.5% lower than that of 15APP/5PT‐Cluster/PP, and the time to pk‐HRR of @IFR/PP was 710 seconds, while that of 15APP/5PT‐Cluster/PP was 580 seconds. The better inhibition effect on HRR and the delay of time to pk‐HRR were caused by the joint‐aggregated structure of @IFR, which can rapidly react to form stable and efficient char layers. This kind of join‐aggregation IFR effect has great significance in suppressing the spread of fire in reality. In addition, @IFR also increased the mechanical properties of PP composites slightly compared with the APP/PT‐Cluster mixture. 相似文献
The effects of aluminum hypophosphite(AHP) as a synergistic agent on the flame retardancy and thermal degradation behavior of intumescent flame retardant polypropylene composites(PP/IFR) containing ammonium polyphosphate(APP) and triazine charring-foaming agent(CFA) were investigated by limiting oxygen index(LOI), UL-94 measurement, thermogravimetric analysis(TGA), cone calorimeter test(CONE), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). It was found that the combination of IFR with AHP exhibited an evident synergistic effect and enhanced the flame retardant efficiency for PP matrix. The specimens with the thickness of 0.8 mm can pass UL-94 V-0 rating and the LOI value reaches 33.5% based on the total loading of flame retardant of 24 wt%, and the optimum mass fraction of AHP/IFR is 1:6. The TGA data revealed that AHP could change the degradation behavior of IFR and PP/IFR system, enhance the thermal stability of the IFR and PP/IFR systems at high temperatures and promote the char residue formation. The CONE results revealed that IFR/AHP blends can efficiently reduce the combustion parameters of PP, such as heat release rate(HRR), total heat release(THR), smoke production rate(SPR) and so on. The morphological structures of char residue demonstrated that AHP is of benefit to the formation of a more compact and homogeneous char layer on the materials surface during burning. The analysis of XPS indicates that AHP may promote the formation of sufficient char on the materials surface and improve the flame retardant properties. 相似文献
A synergistic flame retardant (silicon, phosphorus and nitrogen) based on cyclic polysiloxane, ammonium salt of tetramethylcyclosiloxyl-piperazin-phosphinic acid (APCTSi) was successfully prepared and firmly bonded to cotton fabric through a chemical grafting method. The chemical structure of APCTSi was characterized by Fourier transform infrared (FTIR) spectroscopy, 1H and 31P nuclear magnetic resonance (1H NMR and 31P NMR). The scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX) proved that APCTSi successfully adhered to the surface of cotton fabric and the elements on the surface of cotton fabric were evenly distributed. The flame retardant properties were characterized by limiting oxygen index (LOI), vertical burning test, thermogravimetric (TG) analysis and TG-FTIR. The limiting oxygen index (LOI) can reach 30.9% with a char length of 8.7 cm for the weight gain of APCTSi was 16.2%. The combustion behavior was characterized by cone calorimetry test. The peak heat release rate (pHRR) and total heat release (THR) values of treated cotton fabric decreased by 30% and 48% respectively compared to that of pure cotton fabric. All the results proved that the cotton fabric treated by APCTSi had the flame retardant effect of condensed phase (forming stable char layer) and gas phase (releasing nonflammable gases).
Nanoflaky manganese phosphate (NMP) was synthesized from manganese nitrate and trisodium phosphate dodecahydrate, and used as a synergistic agent on the flame retardancy of polypropylene (PP)/intumescent flame retardant (IFR) system. The thermogravimetric analysis (TGA), real time Fourier-transform infrared (RTFTIR) spectroscopy measurements, cone calorimeter (CONE) and microscale combustion calorimeter (MCC) were used to evaluate the synergistic effects of NMP on PP/IFR system. When IFR + NMP was fixed at 20 wt% in flame retardant PP system, the TGA tests showed that NMP could enhance the thermal stability of PP/IFR system at initial temperature from about room temperature to 440 °C and effectively increase the char residue formation. The RTFTIR results revealed that NMP could clearly change the decomposition behavior of PP in PP/IFR system, which promotes decomposition at the initial temperature from about room temperature to 260 °C and forms more effective barrier layer to protect PP from decomposing at high temperature from about 260 °C to 500 °C. The CONE tests indicated that the addition of NMP in PP/IFR system not only reduced the peak heat release rate (HRR), but also prolonged the ignition time. The MCC results revealed that PP/IFR/NMP system generated less combustion heat over the course of heating than that of PP/IFR system. And scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to explore the char residues of the PP/IFR systems with and without NMP. 相似文献
Intumescent flame retardant (IFR) has received the considerable attention ascribed to the inherent advantages including non‐halogen, low toxicity, low smoke release and environmentally friendly. In this work, a novel charring agent poly (piperazine phenylaminophosphamide) named as PPTA was successfully synthesized and characterized by Fourier transform infrared spectra (FTIR) and X‐ray photoelectron spectroscopy (XPS). Then, a series of flame‐retardant EP samples were prepared by blending with ammonium polyphosphate (APP) and PPTA. Combustion tests include oxygen Index (LOI), vertical Burning Test (UL‐94) and cone calorimeter testing,these test results showed that PPTA greatly enhances the flame retardancy of EP/APP. According to detailed results, EP containing 10 wt% APP had a LOI value of 30.2%,but had no enhancement on UL‐94 rating. However, after both 7.5 wt% APP and 2.5 wt% PPTA were added, EP‐7 passed UL‐94 V‐0 rating with a LOI value of 33.0%. Moreover, the peak heat release rate (PHRR) and peak of smoke product rate (PSPR) of EP‐7 were greatly decreased. Meanwhile, the flame‐retardant mechanism of EP‐7 was investigated by scanning electron microscopy (SEM), thermogravimetric analysis/infrared spectrometry (TG‐IR) and X‐ray photoelectron spectroscopy (XPS). The corresponding results presented PPTA significantly increased the density of char layer, resulting in the good flame retardancy. 相似文献