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1.
Magnesium hydroxide sulfate hydrate whisker flame retardant polyethylene/montmorillonite nanocomposites 总被引:3,自引:0,他引:3
Hongdian Lu Yuan Hu Junfeng Xiao Zhengzhou Wang Zuyao Chen Weicheng Fan 《Journal of Materials Science》2006,41(2):363-367
Flame retardant maleated polyethylene/magnesium hydroxide sulfate hydrate whisker (MAPE/MHSH) composites containing organo-modified
montmorillonite (OMT) were prepared by direct melt intercalation. Their morphology, combustion behaviour and thermal stability
were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), cone calorimetry and thermogravimetric
analyses (TGA). The exfoliation of silicate layers within MAPE has been verified by XRD and TEM images. Cone calorimetry results
indicated that a synergistic flame retardant effect on reducing heat release rate (HRR) occurred when MHSH and OMT were both
present in nanocomposite. The reduction in HRR improved as the mass fraction of OMT was increased from 2 to 10 wt%, but there
was little improvement above 5 wt% OMT loading level. TGA profiles of the nanocomposites revealed that the thermodegradation
stability of the nanocomposites decreased as the OMT fraction increased from 2 to 10 wt%. 相似文献
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采用α,ω-二羟基聚二甲基硅氧烷(107胶)、气相白炭黑、无机阻燃剂聚磷酸铵(APP)等制备了无机阻燃脱醇型单组分室温硫化(RTV-1)硅橡胶,研究了APP用量对脱醇型RTV-1硅橡胶阻燃、物理性能和贮存期的影响,以及APP阻燃脱醇型RTV-1硅橡胶的热稳定性.结果表明,当APP的用量达80份以上时,脱醇型RTV-1硅橡胶才具有阻燃性能.但随着APP用量的增加,脱醇型RTV-1硅橡胶的拉伸强度、扯断伸长率均逐渐下降;当加入80份APP时,脱醇型RTV-1硅橡胶贮存期为9个月以上,APP几乎不影响其贮存的性能.添加了80份APP的阻燃脱醇型RTV-1硅橡胶与未加APP的脱醇型RTV-1硅橡胶相比,初始分解温度下降. 相似文献
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Aerogel is a class of material characterized by its high void content and extreme lightness. Different polymer/clay aerogels have been prepared by a simply freeze–thaw process from a suspension with poly(vinyl alcohol) (PVOH) and clay (Na+-MMT). Low density polymer/clay aerogels modified with flame retardant agents were prepared using a similar approach. The addition of flame retardant agents slightly increased the apparent density of the final composites whereas the compression properties were reduced due to the decrease in the polymer/clay interfacial bonding. An exception was the sample containing Al(OH)3 that exhibited higher modulus and stress at maximum deformation. Regarding thermal properties, the presence of ammonium polyphosphate (APP) or silica gel (SG) significantly slowed the rate of aerogel decomposition at the temperature range from 250 °C to 500 °C while the onset of polymer decomposition was not affected. Fire behavior was analyzed through cone calorimeter suggesting that either the presence of Al(OH)3 or APP reduced the heat release rate of PVOH/clay systems. 相似文献
6.
《Composites Part A》2003,34(9):863-873
Novel glass-reinforced epoxy composites containing a phosphate-based intumescent and inherently flame retardant (cellulosic (Visil, Sateri) and phenol-formaldehyde (Kynol)) fibres have been fabricated. These components are added both as additives in pulverized form and as fibre interdispersed with intumescent as a fabric scrim for partial replacement of glass fibre. Fire testing has been performed using a cone calorimeter at an incident heat flux of 50 kW/m2 and the results have shown that introduction of the intumescent/FR fibre to the matrix can significantly reduce the peak heat release values and smoke intensities evolved by composites. Mechanical testing in tensile and flexural modes of these samples has shown that inclusion of the intumescent/fibre system does not adversely influence their tensile and flexural properties. The effect of heat on mechanical properties has been observed by heating the samples in a furnace at 400 °C for 5 min and tested for their flexural and tensile strength retentions. The charred samples remaining after cone exposure were also tested for stiffness test. Some of the samples retained up to 21% of the initial stiffness after being exposed to high heat flux in the cone calorimeter whereas, the control sample was rendered unusable after cone calorimeter exposure. 相似文献
7.
Surface modification of magnesium hydroxide and its application in flame retardant polypropylene composites 总被引:2,自引:0,他引:2
Xiaolang Chen Jie Yu Shaoyun Guo Shengjun Lu Zhu Luo Min He 《Journal of Materials Science》2009,44(5):1324-1332
In this article, titanate and zinc stearate modified superfine magnesium hydroxide [Mg(OH)2] was filled into polypropylene (PP) as a flame retardant (FR). The structure and morphologies of untreated and treated Mg(OH)2 particles were characterized by Fourier transform infrared (FTIR), wide-angle X-ray diffraction (WAXD), and scanning electron
microscope (SEM). PP/Mg(OH)2 (1:1) composites were also prepared in co-rotating twin-screw extruder, and the effects of treatment agents on the rheological
behavior, mechanical properties, and flame retardancy of PP/Mg(OH)2 composites were studied. The results from FTIR and WAXD show that treatment agents are adsorbed onto the surface of Mg(OH)2 particles. The complex viscosity (η*) values of the composites decrease with the addition of various treatment agents. Surface
treatment agent could significantly improve tensile and impact strength of PP/Mg(OH)2 composites due to its enhanced interfacial adhesion between Mg(OH)2 particles and the PP matrix. According to limiting oxygen index (LOI), titanate treated magnesium hydroxide (MH) greatly
enhanced flame retardancy of PP/Mg(OH)2 composites. 相似文献
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Mechanical properties of HDPE/magnesium hydroxide composites 总被引:13,自引:0,他引:13
Fillers incorporated into polymers for flame retardancy can decrease their mechanical strength. Coating of the filler can enhance the properties of polymer composites. A platy magnesium hydroxide, uncoated, or coated with magnesium stearate or stearic was used as filler in high density polyethylene composites. Tensile and flexural properties were measured. Experimental results were compared with various existing models. Experimental data for both tensile and flexural yield strength showed a good fit to the Pukanszky model. Interfacial interaction was also evaluated through this model. Coating modified tensile and flexural yield strength in different ways. Results were explained by the effect of platelet alignment which was measured by X-ray diffraction. Flexural modulus showed a good fit to the Halpin-Tsai equation, but tensile modulus increased less with filler volume fraction, an effect also believed to relate to filler alignment. Elongation at yield decreased with the addition of filler, more so when coatings were present. This property seemed to be controlled mainly by filler dispersion. 相似文献
10.
《Advanced Powder Technology》2019,30(8):1567-1575
A novel strategy was used for preparation of flame retardant based on biomass debris to improve the flame retardant property of silicone rubber (SR). [(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) was used to modify diatomite by esterification method, and DDP@diatomite was obtained. The structure and morphology of this novel additive was identified using Fourier transform infrared spectroscopy (FTIR), Brunner-Emmet-Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS) together with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. Thermogravimetric (TG) analysis was performed to evaluate the thermal degradation behaviors of diatomite and DDP@diatomite. This novel additive was applied into silicone rubber (SR) composites. Combustion parameters, including heat release rate (HRR), total heat release (THR), smoke production rate (SPR), carbon monoxide (CO), peak smoke production rate (PSPR), peak carbon monoxide (PCO) and vertical burning time, were characterized by cone calorimeter and vertical burning tests. Results indicated that this flame retardant can reduce fire risk and toxicity effectively. TG and X-ray diffraction (XRD) patterns of SR and its composites were also investigated. The inexpensive property of modified diatomite could also expand its fire safe applications. 相似文献
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A flame retardant efficiency of flame retardants; ammonium polyphosphate (APP), magnesium hydroxide (Mg(OH)2), zinc borate (Zb), and combination of APP with Mg(OH)2 and Zb in sisal fiber/polypropylene (PP) composites was investigated using a horizontal burning test and a vertical burning test. In addition, maleic anhydride grafted polypropylene (MAPP) was used as a compatibilizer to enhance the compatibility in the system; i.e. PP-fiber and PP-flame retardants. Thermal, mechanical, and morphological properties of the PP composites were also studied. Adding the flame retardants resulted in improved flame retardancy and thermal stability of the PP composites without deterioration of their mechanical properties. APP and combination of APP with Zb effectively enhanced flame retardancy of the PP composites. No synergistic effect was observed when APP was used in combination with Mg(OH)2. SEM micrographs of PP composites revealed good distribution of flame retardants in PP matrix and good adhesion between sisal fiber and PP matrix. 相似文献
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Silicone rubber composed of diverse vinyl content silicone gums blending were prepared and their mechanical properties were investigated. The silicone rubber composed of diverse vinyl content silicone gums blending whose crosslinking points were concentration distribution exhibited better tearing strength and higher tensile modulus in comparison with single vinyl content gums which were mean distribution. The average molecular weight (Mc) of the silicone rubber composed of diverse vinyl content blending are lower than that of single vinyl molar content 0.16% which was calculated by swelling equilibrium method. The viscoelastic behavior indicated the silicone rubber composed of 0.04% and 0.3% vinyl molar content gums blending possessed perfect flexibility at low temperature because it had the lowest glass transition temperature (Tg), and this sample had the largest storage modulus and loss modulus. 相似文献
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Flame-retardant nanocomposites were prepared from diglycidylphenylphosphate (DGPP) and modified montmorillonite (MMT) clay
blended with DGEBA in different ratio. T
g of all formulations increased with increasing clay content in the respective series while decreasing with increasing DGPP
content. The TGA, LOI, and UL-94 data of all nanocomposites indicated that the materials were thermally stable with high flame
retardancy resulting from synergetic effect of phosphorus and inorganic clay. The XRD analysis of the nanocomposites with
1 and 2% of clay indicated the intercalation of clay while rest of the samples displayed exfoliation at high clay content.
As compared to neat epoxy system, a maximum increase of 59.3, 45.5, and 93% of tensile, flexural, and impact strengths were
observed for the prepared nanocomposites. The SEM analysis of the failure surfaces of all DGPP containing samples showed rough
with ridge patterns and river markings on the fracture surface that serves in improving the mechanical properties. 相似文献
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In this study the applicability of the new flame retardant for the intumescent fire retardant coating (IFRC) daubed on the top of the plywood was investigated. The following are the three kinds of flame retardants used in this study: (1) the artificial mesophase graphite powder (MGP), (2) the sericite (Al4(OH)4(KAlSi3O10)2), and (3) the graphite/sericite mixture. The desirable sizes of MGP and sericite were obtained by sieving, and then the surfaces of MGP and sericite were modified using a mechanofusion system. The MGP and sericite were characterized using a scanning electron microscope (SEM), a particle size analyzer, and an energy dispersive spectrum (EDS). The IFRC, which consisted of 19.8% of the flame retardant, 15% of the dehydrate agent, 18% of the foaming agent, 7.2% of the resin binder, and 40% of the solvent, was prepared and daubed on the top of the plywood. The test of the fire protection of IFRC was conducted using a flammability 45° tester. The IFRC with the flame retardant of the raw MGP (or sericite) was also prepared to study the effects of the size distribution and the configuration of the flame retardant on the capability of fire protection of IFRC. The mass ratio of MGP to sericite also substantially affects the capability of fire protection of IFRC. Most interestingly, the capability of the fire protection of IFRC with the flame retardant of the raw material is better than that of IFRC with the flame retardant of the sieved and surface-modified material. 相似文献
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Sheng-Peng Liu Ji-Ru Ying Xing-Ping Zhou Xiao-Lin Xie Yiu-Wing Mai 《Composites Science and Technology》2009,69(11-12):1873-1879
Isotactic polypropylene (PP)/nano-magnesium hydroxide (nano-MH) composites with 10 wt.% maleic anhydride grafted styrene–ethylene-butylene–styrene tri-block copolymer (SEBS-g-MA) as a compatilizer were prepared by melt extrusion compounding and injection molding. The effects of SEBS-g-MA on dispersion of nano-MHs in PP matrix and interfacial adhesion were studied in order to prepare highly filled PP/MH nanocomposites. The results showed that SEBS-g-MA improved both dispersion of nano-MHs and interfacial adhesion in PP/MH nanocomposites with up to 40 wt.% nano-MHs. The elastic moduli of PP/SEBS-g-MA /MH nanocomposites increased marginally and tensile yield strengths were almost invariant with nano-MH loading. Significant impact toughening of these ternary nanocomposites was, however, achieved due to the cavitation of SEBS-g-MA/MH particles and expansion of voids as well as plastic deformation of the PP matrix. 相似文献
19.
The present work deals with the development of new rigid polypropylene composite foams filled with high amounts of flame-retardant systems based on synthetic hydromagnesite, a basic magnesium carbonate obtained from an industrial by-product. A partially-interconnected cellular structure with a cell size around 100 μm was obtained for the hydromagnesite-filled PP foams. A 40% reduction of this cell size was observed when a small amount of a combination of montmorillonite and graphene layered nanoparticles was added to the hydromagnesite. The combination of hydromagnesite with an intumescent additive (ammonium polyphosphate) and layered nanoparticles led to improved thermal stability. In particular, the intumescent additive delayed the beginning of the thermal decomposition temperature and the layered nanoparticles split the second step of thermal decomposition in a third peak observed at higher temperatures. Improved flame retardancy, measured by means of cone calorimetry, was observed in the samples containing the intumescent additive. A novel normalized parameter, called foam efficiency ratio (FER), which takes into account the expansion ratio of the foam and the relation of its fire properties with that of the base solid, was also analyzed. 相似文献
20.
将超声分散后的硅烷偶联剂3-氨丙基三乙氧基硅烷改性碱式硫酸镁晶须(KH550-MgOSW)分散液加入天然胶乳(NR)中,对其进行补强,制得绿色环保高性能的KH550-MgOSW/NR复合材料。系统研究了KH550-MgOSW/NR复合材料的力学性能、阻燃性能及热稳定性能。结果表明,用KH550改性后的MgOSW与橡胶基体具有很好的相容性。KH550-MgOSW/NR复合材料的力学性能、阻燃性能及热稳定性能均比纯胶有所提高。当KH550-MgOSW与NR质量比为4%时,KH550-MgOSW/NR复合材料的各项性能均达到最佳,300%定伸应力、拉伸强度、撕裂强度、断裂伸长率、交联密度比纯胶胶膜分别提高了25.0%、36.8%、37.3%、11.4%、44.2%,垂直燃烧等级由FV-1提高到了FV-0级,比纯胶的起始热降解温度(T0)、最大热降解温度(Tp)和终止热降解温度(Tf)分别提高了6.2℃、5.2℃和4.1℃。 相似文献