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1.
Abstract

A triazine-based macromolecular hybrid charring agent containing zinc borate (MCA-K-ZB) was synthesized and combined with ammonium polyphosphate (APP) to improve the flame retardancy of polypropylene (PP). The flame retardancy and thermal properties of PP composites were investigated using limited oxygen index, vertical burning test, and thermogravimetric analysis. The results showed APP/MCA-K-ZB can improve the flame retardancy of PP compared with APP/MCA-K/ZB. The morphology of the char residues was investigated by scanning electron microscopy (SEM). The SEM result shows that MCA-K-ZB can improve the compactness and continuity of char residue compared with MCA-K/ZB, therefore improving the flame retardancy of PP composites.  相似文献   

2.
Modified montmorillonite‐containing phytic acid (PA‐MMT) has been prepared by acid treatment and then introduced into unsaturated polyester resin (UPR) with an intumescent flame retardant (IFRs). The flame retardancy and thermal degradation of UPR/IFRs/PA‐MMT were evaluated by a limiting oxygen index (LOI) test, a vertical burning test (UL‐94), a thermogravimetric analysis (TGA), and a cone calorimeter test (CCT). Besides, the mechanical properties were studied by a universal testing machine. The LOI value of UPR/IFRs/PA‐MMT composites was increased to 29.2%. The CCT results indicated that the incorporation of PA‐MMT and IFRs significantly improved the combustion behavior of UPR. The results of the mechanical properties indicated that 1.5 wt% loading of PA‐MMT in UPR/IFRs showed the highest improvement in flexural strength and tensile strength. The flame‐retardant mechanism of PA‐MMT/IFRs was examined and discussed based on the results of combustion behavior and char analysis.  相似文献   

3.
A novel flame retardant containing phosphorous-nitrogen structure, the ammonium salt of 2-hydroxyl-5,5-dimethyl-2,2-oxo-1,3,2-dioxapho sphorinane (PNOH), was synthesized and its structure was characterized by 1H NMR and FTIR spectra. PNOH was used together with ammonium polyphosphate (APP) to prepare a novel intumescent flame retardant (IFR) for polyvinyl alcohol (PVA). When a few amounts (0.5%) of metal chelates were added, the flame retardancy of the IFR-PVA systems was significantly improved, having a high LOI value of 34.2 in a total IFR loading of 15 wt.%. In order to have an understanding of the resulting flame retardant effects, the thermal degradation behaviors of IFR-PVA systems were investigated by thermogravimetric analysis (TGA), and the morphology and structures of residues generated in different conditions were investigated by scanning electronic microscopy (SEM) and FTIR spectra. The results show that NiSAO can promote the thermal stability of the IFR-PVA; the residual char containing polyphosphoric or phosphoric acid is formed during the combustion; the formation of a continuous and dense char layer could inhibit the transmission of heat during contacting with flame and shows good flame retardancy.  相似文献   

4.
A hyperbranched polyamine was prepared using an A2 + B3 approach. It acted as a hyperbranched charring and foaming agent (HCFA) in combination with ammonium polyphosphate (APP) to form a new intumescent flame retardant (IFR) system for polyamide 6 (PA6). Effect of HCFA on flame retardant and thermal degradation properties of IFR‐PA6 was investigated by limiting oxygen index (LOI), UL‐94 vertical burning, cone calorimeter, and thermogravimetric analysis (TGA) tests. The IFR system presented the most effective flame retardancy in PA6 when the weight ratio of APP to HCFA was 2:1. The LOI value of IFR‐PA6 could reach 36.5 with V‐0 rating when the IFR loading was 30 wt%. Even if the loading decreased to 25 wt%, IFR‐PA6 could still maintain V‐0 rating with an LOI value of 31. TGA curves indicated that APP would interact with both PA6 and HCFA in PA6/APP/HCFA composite under heating. The interaction between APP and HCFA improved the char formation ability of IFR system and then much more char was formed for PA6/APP/HCFA composite than for PA6/APP. Therefore, better flame retardancy was achieved. Moreover, the structure and morphology of char residue were studied by Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results indicated that compact and foaming char layer containing P‐O‐C structure was formed for PA6/APP/HCFA system during combustion. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

5.
A novel flame retardant (PSiN), containing silicon and nitrogen, was synthesized using N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and diphenylsilanediol through solution polycondensation and it was added to polycarbonate (PC). The structure and thermal properties of PSiN were characterized by fourier transform infrared spectroscopy and thermogravimetric analysis (TG) tests. The effect of PSiN on the flame retardancy and thermal behaviors of PC was investigated by limited oxygen index (LOI), vertical burning test (UL-94), and TG tests. The results showed that the flame retardancy and the thermal stability of PC are improved with the addition of PSiN. When 1 mass% PSiN and 0.5 mass% diphenylsulfone sulfonate (KSS) are incorporated, the LOI value of PC is found to be 46, and class V-0 of UL-94 test is passed. The char structure observed by scanning electron microscopy indicated that the surface of the char for PC/KSS/PSiN system holds a firmer and denser char structure when compared with neat PC and PC/KSS system.  相似文献   

6.
A series of FR-RPUF composites were prepared by a one-step water foaming process with ammonium polyphosphate (APP) and steel slag (SS) as flame retardants. Thermogravimetric analysis (TG), limiting oxygen index (LOI), UL-94 vertical combustion test, microscale combustion calorimetry (MCC), TG-Fourier transform infrared spectrometry (TG-FTIR), scanning electron microscopy (SEM), Raman spectra and FTIR were used to investigate the thermal stability, flame retardancy, combustion performance, gas phase products, and char residue morphology of FR-RPUF composites. TG test results showed that the initial decomposition temperature (T-5wt%) and char residue rate at 700°C of RPUF/APP/SS composites were significantly enhanced by the addition of APP and SS, and the thermal stability of the composites was improved. Flame retardant test results confirmed the significantly increased LOI values of RPUF/APP/SS composites with V-0 rating. TG-FTIR also confirmed the obviously decreased release of toxic gases and flammable gases in the combustion of RPUF/APP/SS composites. SEM and Raman spectra of char residues for the composites suggested that APP/SS system improved the compactness and graphitization degree of char layer for RPUF/APP/SS composite. The above researches provide a new strategy for the utilization of SS in fire safety engineering.  相似文献   

7.
In this work, ammonium polyphosphate (APP) was microencapsulated by UV‐curable epoxy acrylate (EA) resin. The resulting novel EA‐microencapsulated APP (EA‐APP) was characterized by Fourier transform infrared spectra, X‐ray photoelectron spectroscopy, X‐ray diffraction, scanning electron microscopy, granulometry, and thermogravimetric (TG) analysis. EA‐APP was used to flame retard polypropylene (PP). The water solubility of EA‐APP and the water resistance of PP/EA‐APP systems were investigated. The thermal stability and combustion behaviors of PP/EA‐APP composites were studied through TG and cone calorimeter (CC) tests, respectively. The water resistance test showed that the EA shell could significantly improve the water resistance of PP/APP. TG data illustrated that the char residue of EA‐APP greatly increased by 149% compared with uncoated APP, and the thermal stability of PP/EA‐APP composite was improved because of the microencapsulation of APP, with an increment of 248% for the char residue compared with PP/APP. CC test results indicated that the peak value of heat release rate, the total heat release, and the peak of smoke production rate of PP/EA‐APP decreased in comparison with PP/APP. The mechanism for the improvement of flame retardancy in CC test was discussed based on the experimental results. EA resin containing a large number of hydroxyl groups might promote the dehydration reaction in EA‐APP, which facilitated the formation of char residue and the stabilization of APP. Consequently, the flame‐retardant efficiency for APP was improved because of the presence of EA shell. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

8.
A novel ionic liquid containing phosphorus ([PCMIM]Cl) was synthesized and characterized by FTIR, 1H NMR, 13C NMR and 31P NMR. Moreover, a new intumescent flame retardant (IFR) system, which was composed of [PCMIM]Cl and ammonium polyphosphate (APP), was used to impart flame retardancy and dripping resistance to polypropylene (PP). The flammability and thermal behaviors of intumescent flame‐retarded PP (PP/IFR) composites were evaluated by limiting oxygen index (LOI), UL‐94 test, thermogravimetric analysis (TGA) and cone calorimeter test. It was found that there was an obvious synergistic effect between [PCMIM]Cl and APP. When the weight ratio of [PCMIM]Cl and APP was 1:5 and the total amount of IFR was kept at 30 wt%, LOI value of PP/IFR composite reached 31.8, and V‐0 rating was obtained. Moreover, both the peak heat release rate and the peak mass loss rate of PP/IFR composites decreased significantly relative to PP and PP/APP composite from cone calorimeter analysis. The TGA curves suggested that [PCMIM]Cl had good ability of char formation, and when combined with APP, it could greatly promote the char formation of PP/IFR composites, hence improved the flame retardancy. Additionally, the rheological behaviors and mechanical properties of PP/IFR composites were also investigated, and it was found that [PCMIM]Cl could also serve as an efficient lubricant and compatibilizer between APP and PP, endowing the materials with satisfying processability and mechanical properties. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

9.
The combination of synergistic agent with intumescent flame retardant (IFR) systems provides a promising way to prepare high performance IFR composites. In this study, the effects of the synthetic zeolite 4 A in combination with the IFR system consisting of ammonium polyphosphate (APP) and tris (2-hydroxyethyl) isocynurate (THEIC) on thermal degradation, mechanical properties, flame retardancy and char formation of high-density polyethylene composites were investigated by limiting oxygen index (LOI) measurement, cone calorimetry, scanning electron microscopy and laser Raman spectroscopy. The LOI value of HD/FR/Z-0.5 composite with an optimum content of 0.5 wt. % zeolite 4 A and 25 wt. % of total flame retardant reaches 26.3 %. A low loading of zeolite 4 A can improve the bench-scale combustion performance as determined by cone calorimetry, and promote the formation of more compact char residue with a highly graphitic structure. However, a low loading of zeolite in combination with the IFR system consisting of APP and THEIC produces no significant changes in mechanical performance.  相似文献   

10.
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   

11.
In this work, based on castor oil (CO), flame retardant polyurethane sealants (FRPUS) with ammonium polyphosphate (APP) and aluminum hypophosphite (AHP) were prepared. The synergistic flame retardant effects between APP and AHP on flame retardancy, thermal stability, and flame retardant mechanisms of FRPUS were investigated. It was found that when the mass ratio of APP and AHP was 5:1, the limiting oxygen index (LOI) value of FRPUS increased to 35.1%, In addition, at this ratio, the parameters from cone calorimeter testing (CCT) were reduced; these parameters include peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP). The thermal decomposition behavior of the FRPUS was investigated by thermogravimetric analysis (TGA). The results showed that AHP improved the thermal stability of the PUS/APP system and increased char residue at high temperatures. Moreover, the residual carbon was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM), gas phase pyrolysis products were investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and thermogravimetric analysis/mass spectrometry (TG-MS). It was observed that the flame retardant mechanisms of the APP/AHP system was the combination of gas and condensed phase flame retardant mechanisms.  相似文献   

12.
合成了一种9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)的衍生物——聚苯氧基磷酸-2-10-氢-9-氧杂-磷杂菲基对苯二酚酯(POPP), 以间苯二胺(m-PDA)为固化剂, 环氧树脂(EP)为基料, POPP为阻燃剂, 复配聚磷酸铵(APP), 制备了不同磷含量的阻燃环氧树脂. 利用极限氧指数(LOI)和垂直燃烧(UL94)实验表征了环氧树脂的阻燃性能; 以热重分析、 锥型量热和扫描电镜分析了阻燃环氧树脂的热性能和表面形态. 研究结果表明, 阻燃剂总加入量(质量分数)为5%时即可达到UL94 V-0级, 同时LOI值为27.7%; 当总加入量为15%, 即wPOPP=5%, wAPP=10 %时, 其LOI值可达到33.8%. 随着磷含量的增加, 阻燃环氧树脂的初始降解温度略有降低, 但高温下的残炭率明显增加. POPP/APP的加入在很大程度上降低了环氧树脂的热释放速率、 有效燃烧热、 烟释放量和有毒气体释放量. 阻燃环氧树脂在高温下形成比较稳定的致密膨胀炭层, 为底层的环氧树脂主体隔绝了分解产物及热量和氧气交换, 增强了高温下的热稳定性.  相似文献   

13.
A novel hyperbranched polyamine charring agent (HPCA), a derivative of triazines, was synthesized and well characterized by 1H NMR and FTIR. HPCA and ammonium polyphosphate (APP) were added into polylactide (PLA) resin as an intumescent flame retardant (IFR) system to impart flame retardancy and dripping resistance to PLA. The flammability and thermal stability of IFR-PLA composites were investigated by limiting oxygen index (LOI), UL-94 vertical burning, cone calorimetry and thermogravometric analysis (TGA) tests. The results showed that the IFR system had both excellent flame retardant and anti-dripping abilities for PLA. The TGA curves suggested that HPCA has good ability of char formation and when combined with APP, would induce synergistic effect which could be clearly observed. This effect greatly promoted the char formation of IFR-PLA composites, hence improved the flame retardant property. Additionally, the structure and morphology of char residues were studied by XPS, FTIR and SEM.  相似文献   

14.

A novel phosphorous containing flame retardant epoxy resin is synthesized by modifying the epoxy resin initially with phosphoric acid and further with aluminum hydroxide (ATH) to enhance the fire retardancy of the modified epoxy resin. The several phosphorous modified epoxy resin to ATH mass ratios were used to study the effect of ATH addition on epoxy. Thermal and mechanical properties. The structure of the modified flame retardant epoxy resin was characterized using Fourier-transform infrared spectroscopy (FTIR) while thermal degradation behavior and flame retardant properties were examined using thermo-gravimetric analysis (TGA) and UL-94 testing. Furthermore, ultimate tensile strength and young modulus were analyzed to study the effect of ATH addition on mechanical properties. The findings indicated that fire retardancy of ATH reinforced modified ep oxy resin is higher than virgin and phosphorous modified epoxy resin and depicted eminent flame retardant properties with suitable mechanical properties.

  相似文献   

15.
利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和马来酸酐(MA)对淀粉进行改性得到磷化淀粉(DOPOMASt),通过红外光谱(FTIR)、核磁共振谱(1H-NMR)和X射线光电子能谱(XPS)确定其结构.利用DOPOMASt作为碳源,与聚磷酸铵(APP)复配后通过熔融共混制备了阻燃聚乳酸(PLA)...  相似文献   

16.
A phosphorus and silicon containing liquid monomer (9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide–vinyltrimethoxysilane (DOPO–VTS)) was synthesized by the reaction between DOPO and VTS. DOPO–VTS and methacryloxypropyltrimethoxylsilane were introduced into unsaturated polyester resin to prepare flame retardant UPR/SiO2 (FR‐UPR/SiO2) hybrid materials by sol–gel method and curing process. DOPO–VTS contributes excellent flame retardancy to UPR matrix, which was confirmed by the limiting oxygen index and microscale combustion calorimeter results. The thermogravimetric analysis (TGA) results indicate that the FR‐UPR/SiO2 hybrid materials possess higher thermal stability and residual char yields than those of pure UPR at high temperature region. The thermal degradation of materials was investigated by TGA/infrared spectrometry (TG‐IR) and real‐time infrared spectrometry (RT‐IR), providing insight into the thermal degradation mechanism. Moreover, scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS) were used to explore the morphologies and chemical components of the residual char. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

17.
Herein, a bridged 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) derivative (PN‐DOPO) in combination with organ‐montmorillonite (OMMT) was used to improve the flame retardancy and mechanical properties of glass‐fiber‐reinforced polyamide 6 T (GFPA6T). The flame retardancy and thermal stabilities of the cured GFPA6T composites were investigated using limiting oxygen index, vertical burning (UL‐94) test, cone calorimeter test, and thermogravimetric analysis (TGA). The morphological analysis and chemical composition of the char residues after cone calorimeter tests were characterized via scanning electron microscopy and energy dispersive spectrometry. The results indicate that 2 wt% OMMT combined with 13 wt% PN‐DOPO in GFPA6T achieved a V‐0 rating in UL‐94 test. The peak heat release rate and total smoke release remarkably decreased with the incorporation of OMMT as compared to those of GFPA6T/15 wt% PN‐DOPO. The TGA results show that the thermal stability and residual mass of the samples effectively increased with the increase in OMMT content. The morphological analysis and composition structure of the residues demonstrate that a small amount of OMMT could help form a more thermally stable and compact char layer during combustion. Also, with the incorporation of OMMT, the layers consisted of more carbon‐silicon and aluminum phosphate char in the condensed phase. Furthermore, GFPA6T/PN‐DOPO/OMMT composites exhibited excellent mechanical properties in terms of flexural modulus, flexural strength, and impact strength than the GFPA6T/PN‐DOPO system. The combination of PN‐DOPO and OMMT has improved the flame retardancy and smoke suppression of GFPA6T without compromising the mechanical properties.  相似文献   

18.
The charring agent (CNCA‐DA) containing triazine and benzene rings was combined with ammonium polyphosphate (APP) to form intumescent flame retardant (IFR), and it was occupied to modify polylactide (PLA). The flame retardant properties and mechanism of flame retardant PLA composites were investigated by the limited oxygen index (LOI), vertical burning test (UL‐94), thermogravimetric analysis, microscale combustion calorimetry, scanning electron microscopy, laser Raman spectroscopy analysis and X‐ray photoelectron spectroscopy. The analysis from LOI and UL‐94 presented that the IFR was very effective in flame retardancy of PLA. When the weight ratio of APP to CNCA‐DA was 3:1, and the IFR loading was 30%, the IFR showed the best effect, and the LOI value reached 45.6%. It was found that when 20 wt% IFR was loaded, the flame retardancy of PLA/IFR still passed UL‐94 V‐0 rating, and its LOI value reached 32.8%. The microscale combustion calorimetry results showed that PLA/IFR had lower heat release rate, total heat release, and heat release capacity than other composites, and there was an obvious synergistic effect between APP and CNCA‐DA for PLA. IFR containing APP/CNCA‐DA had good thermal stability and char‐forming ability with the char residue 29.3% at 800°C under N2 atmosphere. Scanning electron microscopy observation further indicated that IFR could promote forming continuous and compact intumescent char layer. The laser Raman spectroscopy analysis and X‐ray photoelectron spectroscopy analysis results indicated that an appropriate graphitization degree of the residue char was formed, and more O and N were remained to form more cross‐linking structure. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

19.
Ammonium polyphosphate (APP) and inorganic fillers were applied for improving flame retardancy and mechanical performance of recycled poly(ethylene terephthalate) (RPET). RPET was compounded with 5–10 wt% of talc and glass bead using twin screw extruder then were injection molded with 2 wt% of APP. The effects of fillers contents and APP on properties and flame retardancy of RPET composites were investigated. The incorporation of talc and glass bead as well as the adding of APP significantly improved tensile and flexural modulus of RPET composites. Scanning electron microscope micrographs indicated good distribution of talc, while glass bead was agglomerated on the RPET matrix. Flame‐retardant property of neat RPET and the RPET composites revealed V‐2 of UL‐94 flammability rating. It can be noted that the composites were less dripping because of the synergistic effect of adding talc and glass bead with APP. From thermogravimetric analysis results, larger of residual char contents and lower values of the activation energy were considered for enhancing flame retardancy in the RPET composites. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

20.
利用原位插层反应制得磷腈类衍生物修饰的改性磷酸锆(F-ZrP),并用机械共混工艺制得阻燃硅橡胶复合材料(FRSR).采用X射线衍射(XRD)、透射电子显微镜(TEM)、傅立叶红外光谱(FTIR)、热重(TG)、扫描电子显微镜(SEM)分别对磷酸锆的结构及其在硅橡胶基体的分散进行表征,并结合FRSR的垂直燃烧(UL-94)、极限氧指数(LOI)、锥形量热测试及残渣表面形貌的观察,研究了不同份数的F-ZrP复配聚磷酸铵对FRSR阻燃性能的影响并和添加未改性磷酸锆的样品性能对比,并对阻燃机理进行初步探讨;最后分析FRSR的力学性能.结果表明:F-ZrP拥有更大的层间距,而且在FRSR中分散的更好;当1 phr F-ZrP和19 phr APP复配使用时,UL-94达V-0级且LOI值为31.4,热释放速率峰值为265.3 kW/m~2,拉伸强度达8.11 MPa,FRSR的阻燃性能和力学性能得到明显的改善.适量的F-ZrP和APP复配使用能在气相和固相发挥协效阻燃作用,F-ZrP与APP的并用能提高残渣质量并且使阻隔层更加紧实,致密.  相似文献   

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