首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A novel amine‐terminated and organophosphorus‐containing compound m‐aminophenylene phenyl phosphine oxide oligomer (APPPOO) was synthesized and used as curing and flame‐retarding agent for epoxy resins. Its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance, and 31P nuclear magnetic resonance. The flame‐retardant properties, combusting performances, and thermal degradation behaviors of the cured epoxy resins were investigated by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter test, and thermogravimetric analysis. The EPO/APPPOO thermosets passed V‐1 rating with the thickness of 3.0 mm and the LOI value reached 34.8%. The thermosets could pass V‐2 rating when the thickness of the samples was 1.6 mm. The cone calorimeter test demonstrated that the parameters of EPO/APPPOO thermosets including heat release rate and total heat release significantly decreased compared with EPO/PDA thermosets. Scanning electron microscopy revealed that the incorporation of APPPOO into epoxy resins obviously accelerated the formation of the compact and stronger char layer to improve flame‐retardant properties of the cured epoxy resins during combustion. The mechanical properties and water resistance of the cured epoxy resins were also measured. After the water‐resistance test, EPO/APPPOO thermosets still remained excellent flame retardant and the water uptake was only 0.4%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41159.  相似文献   

2.
In this study, phospholipidated β‐cyclodextrin (PCD) was obtained by the condensation between β‐cyclodextrin and phenyl phosphonic acid dichloride, which was characterized by Fourier transform infrared (FTIR) spectra, 1H‐NMR, and thermogravimetric analysis (TGA). The thermal stability and flame retardancy of the poly(lactic acid) (PLA) blends [PLA–ammonium polyphosphate (APP)–PCD] were measured by TGA coupled to FTIR spectroscopy, vertical burning test (UL‐94), limiting oxygen index (LOI), and cone calorimetry tests. The results show that the mass ratio and loading amount of APP and PCD affected the properties of PLA. When the loading of APP and PCD was 30 wt % and the mass ratio of APP to PCD was 5:1, the highest LOI value of 42.6% (that of neat PLA was 19.7%) and a UL‐94 V0 rating were achieved, and the reduction of the total heat release was greater than 80%. Even when the total amount of APP and PCD was decreased to 20 wt % with the same mass ratio, the flame‐retardant PLA still can achieved a UL‐94 V0 rating. The improved performance was explained by the formation of an intumescent, continuous, contact char layer. Moreover, the reaction between APP and PCD contributed to the improvement of the thermal stability of the char residue. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46054.  相似文献   

3.
Most flame‐retarded polymer products need to be highly durable throughout their service lifetime in many demanding applications areas such as construction, transportation, electric equipment, and textiles, where low flammability in combination with high resistance toward oxidative deterioration triggered by the action of light, heat, and/or mechanical stress is a mandatory quality. To achieve this, it is essential to better understand the overall interplay (both physical and chemical processes) between different components such as different flame retardant structures in their respective polymers and in the presence of coadditives such as processing stabilizers, antioxidants, light stabilizers, metal deactivators, filler deactivators, ultraviolet absorbers, and so on, in the flame‐retarded polymer product. In this article, the key difficulties in improving weathering resistance of flame‐retarded polymers are reviewed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

4.
A novel flame‐retardant synergist, chitosan/urea compound based phosphonic acid melamine salt (HUMCS), was synthesized and characterized by Fourier transform infrared spectroscopy and 31P‐NMR. Subsequently, HUMCS was added to a fire‐retardant polypropylene (PP) compound containing an intumescent flame‐retardant (IFR) system to improve its flame‐retardant properties. The PP/IFR/HUMCS composites were characterized by limiting oxygen index (LOI) tests, vertical burning tests (UL‐94 tests), microscale combustion calorimetry tests, and thermogravimetric analysis to study the combustion behavior and thermal stability. The addition of 3 wt % HUMCS increased the LOI from 31.4 to 33.0. The addition of HUMCS at a low additive amount reduced the peak heat‐release rate, total heat release, and heat‐release capacity obviously. Furthermore, scanning electron micrographs of char residues revealed that HUMCS could prevent the IFR–PP composites from forming a dense and compact multicell char, which could effectively protect the substrate material from combusting. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40845.  相似文献   

5.
A novel phosphonate flame retardant additive bis(2,6‐dimethyphenyl) phenylphosphonate (BDMPP) was synthesized from phenylphosphonic dichloride and 2,6‐dimethyl phenol, and its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy, 1H and 31P nuclear magnetic resonance. The prepared BDMPP and curing agent m‐phenylenediamine were blended into epoxy resins (EP) to prepare flame retardant EP thermosets. The effect of BDMPP on fire retardancy and thermal degradation behavior of EP/BDMPP thermosets was investigated by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter and thermalgravimetric analysis (TGA). The morphologies of char residues of the EP thermosets were investigated by scanning electron microscopy (SEM) and the water resistant properties of thermosets were evaluated by putting the samples into distilled water at 70°C for 168 h. The results demonstrated that the cured EP/14 wt % BDMPP composites with the phosphorus content of 1.11 wt % successfully passed UL‐94 V‐0 flammability rating and the LOI value was as high as 33.8%. The TGA results indicated that the introduction of BDMPP promoted EP matrix decomposed ahead of time compared with that of pure EP and led to a higher char yield at high temperature. The incorporation of BDMPP enhanced the mechanical properties and reduced the moisture absorption of EP thermosets. The morphological structures of char residue revealed that BDMPP benefited to the formation of a more compact and homogeneous char layer on the materials surface during burning, which prevented the heat transmission and diffusion, limit the production of combustible gases and then lead to the reduction of the heat release rate. After water resistance tests, EP/BDMPP thermosets still remained excellent flame retardancy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42765.  相似文献   

6.
Two charring agents tris (2‐hydrooxyethyl) isocyanurate terephthalic acid ester, (dimer/trimer mixture TT23, and tetramer TT4) were synthesized by using tris (2‐hydrooxyethyl) isocyanurate (THEIC) and terephthalic acid (TPA) as raw materials. These two charring agents were combined with ammonium polyphosphate (APP) to form intumescent flame retardants (IFR) for polylactide (PLA). The thermal stability of IFRs were tested by TGA, it is found that APP/TT4 mixture has a higher thermal stability and a better char forming ability than that of APP/TT23 mixture. The combustion properties and thermal stability of PLA/APP/TT23 and PLA/APP/TT4 composites were evaluated by UL‐94 burning tests, limiting oxygen index (LOI), cone calorimeter tests and TGA, the chemical structure of char residues were analyzed by FTIR and XPS. It can be concluded that PLA with 30 wt % of APP/TT4 (weight ratio 5 : 1) achieved the greatest flame retardancy. Moreover, the continuous and expansionary char layer observed from SEM images proved better char forming ability of TT4 than that of TT23. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42086.  相似文献   

7.
A macromolecular homopolymer (named as Homo‐THEIC) was synthesized through self‐etherification of tris(2‐hydroxyethyl) isocyanurate (THEIC) molecules and used as charring agent. Its chemical structure was characterized by FTIR and 13C‐NMR. The charring agent was mixed with ammonium polyphosphate (APP) and applied in flame retarded polypropylene (PP). Results of UL‐94, LOI, and cone calorimeter test showed that the LOI of flame retarded PP can reach 32.8% and UL‐94 V‐0 rating can be achieved at 30 wt % loading. The heat release rate and smoke production rate during the combustion of PP were substantially reduced. TGA results indicated that the synergistic effect between APP and Homo‐THEIC existed and the addition of intumescent flame retardant (IFR) dramatically enhanced the thermal stability of PP. According to the results of TGA, SEM, TG‐FTIR, FTIR, and Raman, the char forming process of IFR can be separated into three stages: the formation of viscous phosphate ester (T onset?330 °C), the expanding process along with the decomposition of phosphate ester and the release of a large amount of gases (330–480 °C), and the final formation of graphitic‐like char without any expanding feature (480–670 °C). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44663.  相似文献   

8.
A bromobutyl rubber composition containing a variety of conventional flame retardants, such as Saytex (decabromodiphenyl oxide), Sb2O3, chlorinated paraffin wax, and polychloroprene rubber, was prepared and used to coat nylon 6 fabric in a laboratory‐coating device. An attempt was made to evaluate the decomposition profile, the evolved gases, and the kinetics of the decomposition process at a dynamic heating rate with high‐resolution thermogravimetric analysis (HR‐TGA). HR‐TGA was used with mass spectrometry for evolved gas analysis (EGA). The HR‐TGA results were compared with results from conventional thermogravimetric analysis (TGA) at a constant heating rate; the former offered sharp transitions, an economic timescale, and an accurate activation energy. The resolution optimization for stability analysis and the effect of its variation on the kinetic parameters offered better results for HR‐TGA than conventional TGA. A lifetime and temperature relationship was evaluated in HR‐TGA with Toop's method, and it was observed that the shelf life decreased sharply with temperature. The effluents HBr, HCl, Br ·, and Cl ·, generated between 210 and 496°C during EGA, were correlated with the thermal stability and fire‐retardancy behavior of the material. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2051–2057, 2003  相似文献   

9.
By adjusting the molar ratios of antistatic monomer of octyl phenol ethylene oxide acrylate (denoted as AS), rigid monomer of methyl methacrylate (denoted as MMA), and flame‐retardant monomer of 2‐(phosphoryloxymethyl oxyethylene) acrylate (denoted as FR), a series of flame‐retardant antistatic copolymers poly (octyl phenol ethylene oxide acrylate‐co‐methyl methacrylate‐co‐phosphoryloxymethyl oxyethylene acrylate) (donated as AMF) were synthesized through radical polymerization. Among the obtained copolymers, two copolymers, AMF162 (the feed molar ratio of AS, MMA, and FR as 1 : 6 : 2) and AMF1104 (the feed molar ratio of AS, MMA, and FR as 1 : 10 : 4) with different concentrations were added into polypropylene (PP) to prepare PP‐AMF162 and PP‐AMF1104 series of composites. The thermal stability, limiting oxygen index, the antistatic property, and mechanical properties of PP composites were tested and analyzed. PP‐AMF162 series composites have excellent antistatic effect. When the AMF162 content was equal to or <15 wt %, the impact strength of PP‐AMF162 composites was higher than that of pure PP. The results indicated that copolymer AMF162 was a suitable flame‐retardant and antistatic additive for PP. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41677.  相似文献   

10.
Transparent copolymers composed of hexa(allyl 4‐hydroxybenzoate) cyclotriphosphazene (compound 1 ) and styrene as potential halogen‐free, flame‐retardant optical resins were prepared by radical copolymerization. The thermal performances of the cured resins were studied with thermogravimetric analysis; the decomposition mechanism of the copolymers was investigated with integrated thermogravimetry–Fourier transform infrared analysis. Compared with conventional polystyrene, the synthesized copolymers exhibited a higher refractive index and a higher thermal stability both under nitrogen and air atmospheres at elevated temperature, and the visible‐light transmittance of the copolymers decreased slightly. With increasing ratio of compound 1 to styrene in the copolymers, the onset decomposition temperature and the char yield both increased gradually. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

11.
Halogen‐containing flame retardants are not preferred for environmental reasons. Herein, a halogen‐free intumescent flame‐retardant ethylene‐vinyl acetate copolymer (EVA/IFR) system containing organic montmorillonite (OMMT) and graphene nanosheets (GNSs) is fabricated with well dispersion structure, enhanced thermal‐oxidative resistance at high temperature. Interestingly, the amount of residual chars from thermogravimetric analysis is increased to 12.7 wt % at 700 °C, the EVA/IFR composite containing both OMMT and GNSs exhibits the best flame retardancy with the lowest peak heat release rate value of 529.58 kW m?2, and the highest limited oxygen index value of 24.8%. The excellent flame retardancy is attributed to the formation of complete and compact protective char layer. Furthermore, the decreases of the mechanical properties caused by the addition of IFR are relieved and a high volume resistivity is maintained when combining OMMT and GNSs in the EVA/IFR system together. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46361.  相似文献   

12.
The role of dual imidazolium polyoxometalates (POMs) in the flame retardancy of polypropylene/intumescent flame retardant (PP/IFR) composites was studied. The results showed that the structures of dual imidazolium POMs have a great effect on the flame retardancy of PP composites. The dual imidazolium POMs based on an ethyl group (EMIPMA) obtain the best flame retardant efficiency. With 15.5 wt % IFR and 0.5 wt % EMIPMA, the PP composites reach a limiting oxygen index of 25.7 and the UL‐94 V‐0 standard. However, the dual imidazolium POMs containing a butyl (BMIPMA) or hexyl (HMIPMA) group cannot achieve the UL‐94 V‐0 standard at the same formulation. Dual imidazolium POMs not only promote the formation of good char, but also induce the formation of intumescent char with a hierarchical and microporous structure that helps to prevent gas and heat from transferring from the flame to the resin. Therefore, the flame retardancy of PP/IFR composites is improved. However, excessive combustible components produced by BMIPMA or HMIPMA deteriorate the flame retardancy of PP/IFR composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45491.  相似文献   

13.
The flame retardation of polypropylene (PP) composites containing melamine phosphate (MP) and pentaerythritol phosphate (PEPA) was characterized by limiting oxygen index (LOI) and UL 94. The morphology of the char obtained from the combustion of the composites was studied by scanning electron microscopy (SEM). The thermal degradation of the composites was investigated using thermogravimetric (TG) analysis and real‐time Fourier transform infrared (RTFTIR) spectroscopy. It has been found that the PP composites containing only MP do not show good flame retardancy even at 40% additive level. Compared with the PP/MP binary composites, all the LOI values of the PP/MP/PEPA ternary composites at the same additive loading increase, and UL 94 ratings of the ternary composites at suitable MP/PEPA ratios are raised to V‐0 from no rating (PP/MP). The TG and RTFTIR studies indicate that the interaction occurs among MP, PEPA and PP. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

14.
Tri(acryloyloxyethyl)phosphate (TAEP) and di(acryloyloxyethyl)ethyl phosphate (DAEEP) were used as reactive‐type flame‐retardant monomers along with commercial epoxy acrylate and polyurethane acrylate oligomers in ultraviolet (UV)‐curable resins. The concentrations of the monomers were varied from 17 to 50 wt %. The addition of the monomers greatly reduced the viscosity of the oligomers and increased the photopolymerization rates of the resins. The flame retardancy and thermal degradation behavior of the UV‐cured films were investigated with the limiting oxygen index (LOI) and thermogravimetric analysis. The results showed that the thermal stability at high temperatures greater than 400°C and the LOI values of the UV‐cured resins, especially those containing epoxy acrylate, were largely improved by the addition of the monomers. The dynamic mechanical thermal properties of the UV‐cured films were also measured. The results showed that the crosslink density increased along with the concentrations of the monomers. However, the glass‐transition temperature decreased with an increasing concentration of DAEEP because of the reduction in the rigidity of the cured films, whereas the glass‐transition temperature increased with the concentration of TAEP because of the higher crosslink density of the cured films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 185–194, 2005  相似文献   

15.
Resistance to burning is one of the most useful properties that can be imparted to leather. Pyrovatex CP is rich in phosphorus and nitrogen and has been successfully used as a flame‐retardant agent in the presence of etherified methylolated melamine (EMM). The effects of a finishing formulation containing Pyrovatex CP and EMM on the flame retardancy and other properties of modified leather have been studied under different conditions. The synergistic effect of the N/P ratio has been thoroughly investigated through the estimation of the nitrogen and phosphorus contents, and their impact on the flame retardancy, tensile strength, and elongation at break of the treated leather has been studied. An investigation of the different factors has led to the following conclusions: (1) the P and N percentages increase with increasing curing temperature and time, (2) increases in the Pyrovatex CP and EMM concentrations are accompanied by an enhancement of the P and N percentages, and (3) all samples exhibit loss in their tensile properties but within an acceptable range (20%). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006  相似文献   

16.
In this study, several flame retardants (FRs), containing phosphorus, nitrogen, and silicon, were synthesized. These synthesized FRs were blended with polypropylene (PP) to obtain mixture samples. The flame‐retardant properties of these mixture samples were estimated by the limiting oxygen index (LOI) value and thermal stabilities were characterized by thermogravimetric analysis. The LOI values of these samples were improved from 17.0 to 26.0 and the char yield increased from 0 to 27 wt %. A comparison of these samples, with respect to their LOI values and carbon yield, showed that the FRs, which simultaneously contained phosphorus, nitrogen, and silicon elements, can provide materials with the best flame‐retardant properties, suggesting that there is a synergistic effect among the three elements on the flame‐retardant properties and char yield when they are used in PP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 854–860, 2005  相似文献   

17.
The thermal degradation behavior of the blend based on polylactide (PLA) and poly(1,2‐propanediol 2‐carboxyethyl phenyl phosphinate) (PCPP) was investigated by the thermogravimetric analysis (TGA). Thermal degradation activation energies (Ea) of neat PLA and PLA/15% PCPP blend were calculated via the Flynn–Wall–Ozawa method. The Ea of the blends increased with the addition of PCPP increasing when the conversion was higher than 10%. In addition, the appropriate conversion models for the thermal degradation process of PLA and PLA/15% PCPP were studied via the Criado method. At the same time, the main gaseous decomposition products of PLA and its blend were identified by TGA/infrared spectrometry (TGA–FTIR) analysis. And it revealed that the PCPP improved the flame‐retardant property of PLA via altering the release of the flammable gas and nonflammable gas. Moreover, the PCPP improved the flame‐retardant property of PLA by inhibiting exothermic oxidation reactions in the combustion, which was further proved by pyrolysis–gas chromatography–mass spectrometry analysis. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40480.  相似文献   

18.
A hyperbranched charring agent (CT) was synthesized by triglycidyl isocyanurate and diethylenetriamine in water, and a new intumescent flame retardant (IFR) system was formed by ammonium polyphosphate (APP) and CT. The different formula and synergistic system between IFR and aluminum hypophosphite (AHP) have been studied through limit oxygen index (LOI), UL‐94, cone calorimetry test and TGA. It was found that the LOI for poly(lactic acid) (PLA) with 30 APP/CT (4:1) and 20 wt % IFR/AHP (3:1) were 41.2% and 43.5%, respectively, and the both could achieve UL‐94V‐0 rating with no melt dripping. The heat release rate (HRR), maximum HRR value and average mass loss rate of PLA could be dramatically decreased by combination of IFR and AHP while the thermal stability was greatly enhanced. The study of morphology and structure of char illustrated that more intumescent and compact char layer with good intensity was formed during the degradation of IFR/AHP, which resulting to better flame retardancy and anti‐dripping than IFR or AHP alone. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46359.  相似文献   

19.
A novel phosphorus?nitrogen flame retardant, octahydro‐2,7‐di(N,N‐dimethylamino)‐1,6,3,8,2,7‐dioxadiazadiphosphecine (ODDP), with bi‐phosphonyl in a cyclic compound, was synthesized by the reaction of POCl3, NH(CH3)2·HCl with OHCH2CH2NH2 in CH2Cl2 solution, and characterized by Fourier transform infrared spectrometer, nuclear magnetic resonance, and mass spectrum. ODDP has been successfully reacted with polyurethane (PU) as a chain extender to prepare phosphorus–nitrogen synergistic halogen‐free flame‐retardant waterborne PU (DPWPU). Limiting oxygen index (LOI), UL‐94, thermogravimetric analysis and scanning electron microscopy suggest the excellent flame retardancy of the DPWPU polymer. When the content of ODDP was 15 wt %, the LOI of DPWPU was 30.6% and UL‐94 achieved a V‐0 classification. Compared with the unmodified WPU, the thermodecomposition temperature of the DPWPU was reduced and the amount of carbon residue was increased to 18.18%. The surface of carbon residue was shown to be compact and smooth without holes, which would be favorable for resisting oxygen and heat. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41288.  相似文献   

20.
Acrylonitrile‐butadiene‐styrene (ABS) resins are widely used in many sectors of the industry due to excellent mechanical properties, low temperature resistance, heat resistance, and chemical resistance. However, its flammability constitutes a key limitation in their applications. Consequently, development of flame‐retarding ABS resins is imperative. Herein, we report a novel synergistic system composed of Mg–Al–Co–layered double hydroxides (LDHs) prepared via a co‐precipitation method, and [4‐(diphenoxy‐phosphorylamino)‐6‐phenyl‐[l,3,5] triazin‐2‐y1]‐phosphoramidic acid diphenyl ester (DPCPB), a novel intumescent flame retardant. The properties of the as‐prepared LDHs/DPCPB/ABS composites are evaluated using standard combustion performance tests including limiting oxygen index (LOI) and vertical burning test (UL‐94). Novel ABS resins with the composition of ABS/DPCPB = 100/25 and ABS/DPCPB/LDHs = 100/2l/4 exhibit higher LOIs, 23.9 and 24.7, respectively, compared to 18.1 for the pure ABS. Meanwhile, they meet the V‐2 and A‐1 level, respectively, in UL‐94 tests. Moreover, the prepared composites exert flame‐retarding effects in gas phase and condensed phase simultaneously. Our results reveal synergistic effects between Mg–Al–Co–LDHs and DPCPB for the flame retardation of ABS resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46319.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号