ATH/OMMT复合改性沥青阻燃抑烟性能与机理分析

对ATH、OMMT改性沥青的阻燃抑烟性能进行了研究,将ATH、OMMT两种改性剂按照不同配比进行复配,研究了不同配比的复合阻燃剂对沥青常规性能、阻燃抑烟性能的影响,评价了不同配比复合阻燃剂的协同效果,并采用X射线衍射(XRD)、红外光谱(FTIR)等手段研究了沥青改性前后的微观结构变化,采用扫描电镜(SEM)、X射线能谱仪(EDS)等手段研究了沥青燃烧后的碳层结构及元素组成,探究了ATH/OMMT复合阻燃体系的阻燃机理.结果 表明,单掺OMMT对沥青阻燃抑烟性能的提升非常有限,而单掺ATH虽然能有效提高沥青的阻燃性能但需要的掺量较大.OMMT与ATH间存在良好的协同效果,能够有效提高沥青的阻燃性能和抑烟性能.不同掺量(1％、3％、5％)的OMMT在SBS改性沥青中均形成了剥离型纳米复合材料,在OMMT改性沥青的红外光谱中,1 092 cm-1、1 032 cm-1、517 cm-1、463 cm-1四处特征峰的峰面积指数与沥青中OMMT掺量之间展现出良好的线性关系.在ATH/OMMT复合阻燃抑烟沥青的热解燃烧过程中,ATH受热产生的Al2 O3依附于聚集在沥青表面的OMMT片层上,形成了一种耐火的致密复合阻隔层,可以高效地阻隔沥青燃烧过程中的热量及物质传递,减少了可燃轻质组分的析出量,增加了成碳比例,使得ATH/OMMT复合改性沥青具备良好的阻燃抑烟性能.     

复合型阻燃剂对聚氯乙烯的阻燃抑烟作用研究

采用微胶囊红磷（MRP）、硼酸锌（ZnBO3）、氢氧化铝(ATH)和氢氧化镁(MH)进行复配对软质聚氯乙烯（PVC）进行阻燃处理,通过极限氧指数、热失重、锥形量热方法研究了不同配比阻燃剂对PVC的阻燃抑烟性能的影响。结果表明,当PVC/MRP/ZnBO3/ATH/MH质量比为100:3:1:20:20时,具有良好的阻燃抑烟效果,极限氧指数可达35.9 %;阻燃体系PVC/ATH/MH、PVC/MRP/ZnBO3/ATH/MH相对于纯PVC具有良好的阻燃抑烟性,PVC/MRP/ZnBO3/ATH/MH比PVC/ATH/MH体系在热释放、烟气、一氧化碳和二氧化碳排放指标上数值更低,热稳定性增加,成炭率更高,火灾性能指数提高,火灾蔓延指数减小,火灾危险性降低。     

阻燃改性沥青及其混合料性能探析

为了降低沥青在封闭环境中的燃烧风险,本文选用氢氧化铝(ATH)及氢氧化镁(MH)阻燃剂作为主要的阻燃改性剂对基质沥青和SBS改性沥青进行改性,制备了具备阻燃性能的沥青材料,采用氧指数试验全面评价不同类型阻燃改性沥青的阻燃性能,并采用马歇尔试件燃烧试验对其阻燃性能进行验证,在此基础上,采用高温稳定性试验及低温抗裂性试验评价阻燃改性沥青混合料的路用性能。     

阻燃剂表面改性对阻燃沥青性能的影响

为提高阻燃剂与沥青的相容性,对阻燃剂进行表面改性并用于制备阻燃沥青.通过沥青氧指数试验、软化点试验、动态剪切流变试验、延度试验和离析试验评价阻燃剂对沥青阻燃性能、高、低温性能及储存稳定性的影响并确定最佳掺量.借助热重(TG)和扫描电镜(SEM)分析阻燃剂的表面改性机理和阻燃机理.结果表明,阻燃剂可以显著提高沥青的阻燃性能和高温性能,当掺量不超过8%,对沥青的低温性能和储存稳定性影响较小;阻燃剂可以促进沥青成炭,减少沥青燃烧时气体挥发物的逸出;表面改性会提高阻燃剂的分散性和阻燃沥青的热稳定性,改善阻燃沥青的阻燃性能和低温性能.     

ATH和APP对聚乳酸/竹粉复合材料阻燃抑烟性能的影响

利用竹粉和聚乳酸为原料复合制备聚乳酸/竹粉复合材料,分别采用氢氧化铝(ATH)和聚磷酸铵(APP)阻燃剂对聚乳酸/竹粉复合材料进行阻燃抑烟处理并对阻燃处理后的复合材料进行性能测试。结果表明,两种阻燃剂的加入均使复合材料高温下的成炭率提高了约2倍,分别达到了24.7%和25.6%;ATH和APP的加入均有效提高了聚乳酸/竹粉复合材料的阻燃性能;其中,APP对复合材料燃烧过程中热量释放的抑制明显,其热释放速率在燃烧100s以后下降了近2倍,约为150kW/m2,但生烟量大;而ATH对复合材料的抑热效果不及APP,但抑烟效果显著,平均烟释放速率只有约0.02m2/s。     

无机硅化合物与磷杂菲/硼酸酯双基分子复合阻燃环氧树脂的研究

将磷杂菲/硼酸酯双基分子复合阻燃剂(ODOPB-Borate)分别与有机改性蒙脱土(OMMT)和二氧化硅(SiO_2)复配制备了阻燃环氧树脂(EP)。并通过热失重、极限氧指数、锥形量热燃烧实验、扫描电子显微镜等研究了含硅无卤阻燃剂OMMT、SiO_2与ODOPB-Borate的协同作用对EP阻燃性能的改善。结果表明,OMMT,SiO_2分别与ODOPB-Borate复配可有效提高EP的阻燃性能,当阻燃剂的添加量为4%(质量分数,下同),且OMMT/ODOPB-Borate和SiO_2/ODOPB-Borate的质量比均为1∶7时,EP的极限氧指数分别提升到38.8%和38.5%,达到UL 94 V-0级;OMMT和SiO_2的添加降低了EP/ODOPB-Borate体系的热释放速率(HRR),提高了其阻燃体系的屏障保护作用,并优化了气相和凝聚相阻燃效应的分配,证实了OMMT和SiO_2与ODOPB-Borate之间存在协同阻燃效应。     

电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。     

阻燃处理对竹粉增强聚乳酸复合材料阻燃抑烟性能影响

分别采用氢氧化铝(ATH)、聚磷酸铵(APP)及ATH+ APP复合阻燃剂对竹粉增强聚乳酸复合材料进行阻燃抑烟处理,并对处理后的复合材料性能进行测试与表征.结果表明,两种阻燃剂均显著增加了复合材料的成炭率,ATH+ APP产生了协同作用,使复合材料成炭率提高了近4倍,达到了45.3％;复合材料经阻燃处理后其阻燃性能均得到了不同程度的提升.其中,APP对复合材料燃烧过程中热量释放的抑制作用最明显,ATH对复合材料表现出了较强的抑烟效果,而ATH +APP复合阻燃剂产生的协同作用使复合材料具有阻燃和抑烟的双重特性.     

膨胀型阻燃剂包覆EPS泡沫的阻燃抑烟性能

采用树脂包覆法,用蜜胺树脂和聚磷酸铵/季戊四醇/三聚氰胺组成的膨胀型阻燃剂制备无卤阻燃发泡聚苯乙烯(EPS)泡沫,研究膨胀阻燃剂对EPS泡沫的阻燃性能、抑烟性能及力学性能的影响。结果表明,膨胀阻燃剂可以有效提高EPS泡沫的阻燃性能和抑烟性能,极限氧指数最高可提高到30.6%,UL-94达到V-0等级,生烟量下降35%,EPS泡沫的冲击强度也得到提高。     

氢氧化铝表面改性对阻燃硅橡胶性能的影响

研究了改性氢氧化铝(ATH)对阻燃硅橡胶性能的影响。结果发现:以六甲基二硅氮烷(HMDS)为表面改性剂可以使ATH实现表面有机化,增加ATH与硅橡胶的相容性,有效提高阻燃硅橡胶的力学性能。其中,采用工艺3获得的活性ATH 3#对硅橡胶的力学性能影响显著,拉伸强度提高18%。表面改性有效提高了ATH在硅橡胶中的分散均匀性。氧指数测试结果表明,氢氧化铝表面改性对硅橡胶阻燃性能基本没有影响。采用改性ATH与聚磷酸铵作为复配阻燃剂,显著提高了硅橡胶的阻燃性能。当复合阻燃剂的用量60份时,硅橡胶的氧指数为40%,离火自熄时间由63 s缩短至2 s。     

阻燃LGFPP的阻燃性能研究

将有机蒙脱土(OMMT)和水滑石(LDH)分别与膨胀阻燃剂(IFR)构成阻燃体系,对长玻纤增强聚丙烯(LGFPP)复合材料进行阻燃改性,通过极限氧指数(LOI)和锥形量热仪(CONE)测试,对比研究了两种体系阻燃LGFPP的阻燃性能及阻燃机理。结果表明:当OMMT质量分数为2%时,复合材料的LOI达到最大值24.2%,且垂直燃烧达到了UL-94 V-0级;当LDH质量分数为1%时,LOI达到最大值23.3%,而垂直燃烧等级仍为V-1级。以炭层阻隔的IFR/OMMT体系比以稀释阻燃的IFR/LDH体系更加有效地改善LGFPP的阻燃性能。     

OMMT对LGFPP/IFR阻燃性能、燃烧性能及力学性能的影响

采用熔融共混技术制备了长玻璃纤维增强聚丙烯/膨胀阻燃剂/有机蒙脱土(LGFPP/IFR/OMMT)复合材料。利用极限氧指数(LOI)、锥形量热仪(CONE)以及万能力学试验机,表征了LGFPP/IFR/OMMT复合材料的阻燃性能、燃烧性能以及力学性能。氧指数测试结果表明,OMMT使LGFPP/IFR体系的氧指数提高。当添加2%OMMT时,LGFPP/IFR/OMMT复合材料的氧指数提高至24.2%。锥形量热仪测试结果表明,LGFPP/IFR体系的热释放速率峰值(PHRR)、烟雾生产率(THR)及引燃时间(TTI)均由于添加OMMT而大幅度降低。力学性能测试结果表明,LGFPP/IFR体系的拉伸强度、弯曲强度以及缺口冲击强度因OMMT的添加,分别提高了8.15%、9.04%和24%,使LGFPP/IFR体系中由于IFR引起LGFPP力学性能降低的弊端得到了明显改善。     

尼龙6/有机蒙脱土阻燃复合材料的结构与性能

将尼龙6、有机蒙脱土和阻燃剂（氢氧化镁、氨基硅油、十溴联苯醚和三氧化二锑、三聚氰胺焦磷酸盐、三聚氰胺磷酸盐）通过熔融插层法直接制备了尼龙6／有机蒙脱土阻燃复合材料。通过X射线衍射（XRD）、力学性能测试、极限氧指数（LOI）测试研究了蒙脱土在复合材料内的分散、复合材料的力学性能以及阻燃性能。结果表明：氨基硅油与有机蒙脱土具有阻燃协同效应，当氨基硅油和有机蒙脱土质量分数分别为2％和5％时，复合材料的LOI高达34％。氢氧化镁、氨基硅油与有机蒙脱土三者具有极强的阻燃协同效应，当氢氧化镁用量分别为30％、40％、50％时，阻燃复合材料的LOI分别为63％、60％、70％。     

Experimental investigation of related properties of asphalt binders containing various flame retardants

The improved flame retardancy of asphalt binders containing various kinds of flame retardants including antimony trioxide, decabromodiphenyl ether (EBPED), aluminium trihydroxide (ATH) and zinc borate (ZB) under different additive concentrations was investigated by limited oxygen index (LOI) and differential scanning calorimetry (DSC) test. To assess the effects of the type and concentration of the flame retardants on rheological properties of asphalt binders, the softening point, penetration, ductility, storage stability and viscosity were tested. The thin film oven test (TFOT) was used to investigate the effect of short-term oxidation on flame-resistant asphalt binders. Experimental results indicated that all of selected flame retardants had a relatively small effect of rheological properties of the asphalt binders, but a great effect on flame retardancy. Asphalt binder with LOI of 25.9 was obtained by adding 6 wt% mixed flame retardants of EBPED: antimony trioxide: ZB=3:1:1 by mass. Asphalt binder was transformed from inflammable materials into flame retardant materials. Therefore, the asphalt binder with both good flame retardancy and rheological properties is a novel road functional material to meet two respects' demands as flame retardant materials and road materials at the same time.     

Effects of the loading levels of organically modified montmorillonite on the flame‐retardant properties of asphalt

The flame‐retardant properties of asphalt for some building applications are very important. In this study, we mainly focused on the influence of organically modified montmorillonite (OMMT) on the flame‐retardant and other properties of asphalt in a large content range and explored suitable contents of OMMT for modified asphalts. Modified asphalts with different contents of OMMT from 2 to 15 wt % were prepared by melt blending. The X‐ray diffraction results revealed that the intercalated structure was formed in the OMMT‐modified asphalt. Rubber processing analysis results indicated the formation of a filler–network structure in the OMMT‐modified asphalt. The limiting oxygen index and cone calorimetry results suggested that OMMT could be used as efficient and ideal flame retardants of asphalt. The results also reveal that excess OMMT contents (i.e., >10 wt %) depredated the flame‐retardant performance of the modified asphalt. We analyzed the mechanism by taking into account of the features of the modified agent for OMMT. The experimental data showed that the viscosity, softening point, and penetration index of the OMMT‐modified asphalt increased with increasing OMMT content, but the ductility decreased slightly when the OMMT content was not beyond 7 wt %. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 10.1002/app.40972.     

Research on the related properties of EVM/Al(OH)3/SiO2 composites applied for halogen‐free flame retardant cable insulation and jacket

The halogen‐free flame retardant (HFFR) ethylene‐vinyl acetate copolymer (EVM)/ATH/SiO₂ composites have been prepared by melting compounding method, and the flame retardant, thermal stability, rheological, electrical, and mechanical properties have been investigated by cone calorimeter, LOI, UL‐94, TG, FE‐SEM, rotational rheometer, dielectric breakdown, and ultimate tensile. The results indicate that the flame retardant of EVM vulcanizates is improved and the fire jeopardizing is dramatically reduced due to the addition of ATH. It is necessary that sufficient loading of ATH (≥120 phr) is needed to reach essential level (LOI > 30; V‐0 rating) of flame retardant for HFFR EVM/ATH/SiO₂ composites used as cable in industry. The rheological characteristics show that at all the measurement frequencies, the storage and loss modulus of the composites increase monotonously as the concentration of ATH filler increases, while the complex viscosity and tan delta present reverse trend. And also, it has been found that the HFFR composites at high filler concentrations still keep good mechanical and electrical properties, which is very important for practical applications as cable. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Flame retardancy and thermal stability of ethylene-vinyl acetate copolymer nanocomposites with alumina trihydrate and montmorillonite

The development of fire retardant for wire and cable sheathing materials has oriented toward low smoke and halogen-free flame retardant technology to achieve better safety for electrical equipment and devices and to satisfy standards. However, many polymer flame resistance materials require a very high proportion of metal hydrate filler within the polymer matrix (60 wt%) to achieve a suitable level of flame resistance, which may lead to inflexibility, poor mechanical properties and problems during compounding and processing. In this study, the alumina trihydrate (ATH) was added to montmorillonite (MMT) as the halogen-free flame retardant of ethylene-vinyl acetate (EVA) copolymer, with various ratios of EVA/ATH/MMT. The prepared nanocomposites were characterized through various techniques of XRD, tensile test, DSC analysis, TGA, LOI evaluation, and FE-SEM to explore the effects of organic modified clay (OMMT) and the layer distance on the mechanical, thermal, and flame resistance properties. In the XRD examinations, the layer-distance of MMT increased from 1.27 to 1.96 nm when polymer was added to the octadecylamine modified MMT. The best tensile strength was obtained at 3 wt% MMT. In addition, the halogen-free flame resistance grade of EVA containing 3 wt% OMMT and 47 wt% ATH revealed the best elongation and fire resistance (LOI = 28). The tensile and flame resistance properties of the nanocomposites were also significantly improved.     

Synergistic Effect of Montmorillonite and Intumescent Flame Retardant on Flame Retardance Enhancement of ABS

The synergistic effects of organic montmorillonite (OMMT) and intumescent flame retardant (IFR) based on the ammonium polyphosphate (APP) and pentaerythritol (PER) on flame retardant enhancement of acrylonitrile-butadiene-styrene copolymer (ABS) were investigated by using the limiting oxygen index (LOI), the UL-94 (vertical flame) test, thermogravimetric analysis (TGA), x-ray diffractometry (XRD) and scanning electron microscopy (SEM). The LOI data and vertical flame tests show that OMMT has a synergistic flame retardant effect with IFR and the LOI value of ABS/OMMT/IFR (96/4/20) reaches 28.7%. The TGA data demonstrate that the incorporation of OMMT and IFR is very effective in enhancing the thermal stability of ABS/OMMT/IFR system at high temperature (T > 500°C). The results of XRD show that the composite of ABS/OMMT is a kind of intercalated nanocomposite and the gallery height of ABS/OMMT nanocomposite is 3.5 nm. The microstructures observed by SEM demonstrate that a suitable amount of OMMT with IFR can promote formation of compact intumescent charred layers in ABS blends.     

增韧改性阻燃聚丙烯的制备以及性能研究

将多聚磷酸铵、季戊四醇、三聚氰胺及有机化蒙脱土通过160℃预混制备了膨胀型阻燃剂(IFR),马来酸酐接枝聚丙烯(PP-g-MAH)为增容剂,选用SBS、EVA、CPE、MBS分别对PP进行增韧改性,采用熔融插层法制备了阻燃聚丙烯(FRPP)。利用了TGA、LOI、SEM和力学性能测试等研究了不同种类的增韧剂和不同OMMT含量对阻燃PP的热稳定性能、阻燃性能、力学性能的影响。结果表明:加入IFR,PP的极限氧指数由17%升为31%,其中CPE体系的极限氧指数达到31%;体系的起始分解温度由纯PP的440.8℃升高到459.5℃,600℃的残炭率比纯PP提高15%以上。SBS的加入,使体系韧性改善最明显,其中OMMT对SBS增韧体系的拉伸强度有改善,对其他增韧体系反而降低拉伸强度。综合FRPP性能,采用SBS为体系的增韧剂,添加1phr OMMT,可以在提高体系的韧性同时,阻燃性能和拉伸性能可以得到进一步的改善。