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采用简单方法制备了苯基次膦酸镧(LaP),并将其作为阻燃剂引入聚乳酸(PLA)中,制备了一系列PLA/LaP复合材料。采用热重分析(TG)、极限氧指数(LOI)、UL 94垂直燃烧、微型量热测试(MCC)等方法研究PLA/LaP复合材料的热稳定性、阻燃性能和燃烧性能。结果表明,LaP可以提高复合材料阻燃性能,30 %(质量分数,下同)的LaP使得复合材料的极限氧指数达到24.8 %,并通过UL 94 V-2级别;LaP可明显提高复合材料的热分解温度和成炭率;高添加量LaP可显著降低复合材料的热释放速率峰值(pHRR)和总热释放(THR),有效降低了复合材料的火灾危险性。 相似文献
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采用简单方法合成苯基次膦酸铈(CeP),并将其作为阻燃剂加入聚乳酸(PLA)中,通过熔融共混技术制备聚乳酸/苯基次膦酸铈(PLA/CeP)复合材料。通过热重(TG)、极限氧指数(LOI)、UL-94垂直燃烧(UL-94)、微型量热(MCC)研究复合材料的热稳定性、阻燃性能和燃烧性能。通过阻燃测试发现,CeP能够提高复合材料阻燃性能,PLA/CeP20极限氧指数能达到24.3%并通过UL-94 V-2级别。热重分析的结果表明,CeP显著提高了PLA/CeP复合材料初始分解温度和成炭率。MCC测试结果表明,CeP能明显降低PLA/CeP复合材料火灾危险性。PLA/CeP20热释放速率峰值(PHRR)和总热释放(THR)分别为397 W/g和13.6 kJ/g,与纯聚乳酸相比,分别下降了13.9%和28.0%。因此,苯基次磷酸铈对聚乳酸具有良好的阻燃效果。 相似文献
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介绍了聚乳酸的合成方法和几类常见的天然纤维的成分结构等特性,综述了聚乳酸/天然纤维复合材料常见的制备方法。重点论述了聚乳酸/麻纤维复合材料、聚乳酸/椰壳纤维复合材料以及聚乳酸/竹纤维复合材料的制备过程以及阻燃性能的研究。论述了纤维的处理,阻燃剂的添加以及制备工艺对复合材料阻燃性能的影响,揭示了各种复合材料的阻燃机理,进而总结了影响阻燃性能的重要因素和调节方法。提供了提高天然可降解纤维复合材料的阻燃性能的有效方法并总结了现阶段研究的不足,对未来的研究方向进行了展望。 相似文献
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在水相中以苯膦二氯和十八水硫酸铝为原料,采用一步法反应,合成了无卤阻燃剂苯基次膦酸铝(BPAAl)。采用1HNMR、31PNMR、FTIR、ICP对产品结构进行表征,并对其反应条件进行探讨,得到最优条件为:苯膦二氯滴加温度5℃,反应温度90℃、反应时间3 h,硫酸铝浓度3 mol/L,在该条件下产率达89.6%。热重分析结果表明,产品起始失重温度在350℃,热稳定性好,具备优良阻燃剂的特征。并研究了BPA-Al在尼龙6中的应用,结果表明,添加量达到10%时,经过阻燃改性的PA6材料极限氧指数达到30%、UL94垂直燃烧达到V-0级,阻燃性能显著提高;拉伸强度达到84.9 k Pa,力学性能好。 相似文献
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采用共沉淀法合成了苯基次膦酸锌(ZnP)并对其进行表征,在此基础上通过熔融共混技术制备了一系列聚乳酸/苯基次膦酸锌(PLA/ZnP)复合材料,采用热重分析,极限氧指数测试(LOI),UL 94垂直燃烧测试、微型量热(MCC)研究ZnP对复合材料热稳定性、阻燃性能以及燃烧性能的影响。研究表明,ZnP可以提高复合材料的热分解温度和成炭性,30 %(质量分数,下同)ZnP使得复合材料的分解温度相对于纯PLA上升8 ℃,750 ℃成炭率达到18.5 %;此外,ZnP可以提高复合材料阻燃性能,PLA/ZnP30的极限氧指数达到24.0 %,并通过UL 94 V-2级别,热释放速率峰值相对于PLA降低了24.9 %,有效提高了复合材料火灾安全性。 相似文献
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《塑料科技》2017,(9):50-54
将碳微球(CMSs)及聚磷酸铵(APP)添加至聚丙烯(PP)中,制备了PP复合材料。采用极限氧指数(LOI)、热重分析仪(TGA)、锥形量热仪(CONE)及电子万能试验机(EUT)等表征手段对PP复合材料的阻燃性能、热稳定性能以及力学性能进行了测试分析,考察了APP与CMSs的质量比以及添加量对PP阻燃体系性能的影响。结果表明:在APP与CMSs质量比为4:1,总添加量为30%时,PP/CMSs/APP复合材料的LOI为28.7%,较纯PP提高了59.4%;火灾性能指数(FPI)值较纯PP提高了约5倍;热释放速率峰值(PHRR)、总热释放量(THR)、平均热释放速率(MHRR)和平均有效燃烧热(MEHC)分别较纯PP降低了31.11%、14.2%、24.5%和32.1%;火灾蔓延指数(FGI)值较纯PP降低了55.3%,且复合材料的热稳定性有所提高,成炭能力显著提升,PP的阻燃性能得到明显改善。 相似文献
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以水为反应介质、无水乙醇为溶剂,将正硅酸四乙酯(TEOS)制备成二氧化硅(SiO_2)溶胶,利用溶胶的网络结构对三聚氰胺氰尿酸盐(MCA)进行表面包覆,制备出包覆型MCA阻燃剂;通过熔融共混方式,将包覆前后MCA与聚己内酰胺(PA 6)切片混合制备成不同阻燃剂含量的阻燃PA 6复合材料;采用红外光谱仪X射线光电子能谱仪、差示扫描量热仪、热重分析仪、垂直燃烧法和极限氧指数法等研究了阻燃PA 6复合材料的结构、热性能及阻燃性能。结果表明:SiO_2溶胶成功接枝在MCA表面,且主要分子结构没有发生改变;随着阻燃剂含量的增加,PA 6复合材料的熔点均有降低,但下降幅度较小;包覆型MCA在材料燃烧过程中能够有效参与成炭,在材料表面形成致密的保护层,增强PA 6复合材料的凝聚相阻燃效果,提高其阻燃性能;随着阻燃剂含量增加,PA 6复合材料的阻燃性逐步提高,添加包覆型MCA质量分数为8%时,PA 6复合材料阻燃性可达到UL-94 V-0等级,极限氧指数为28%。 相似文献
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Preparation of microencapsulated aluminum hypophosphite and flame retardancy and mechanical properties of flame‐retardant ABS composites
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Microencapsulated aluminum hypophosphite (MFAHP) with a shell of melamine–formaldehyde resin (MF) was prepared via in situ condensation polymerization. The presence of MFAHP increased the water resistance of flame‐retarded (FR) acrylonitrile–butadiene–styrene (ABS) composites after hot water treatment. The mechanical properties indicate that the tensile strength and flexural strength of the FR ABS/MFAHP composites is enhanced with the incorporation of MFAHP. Cone calorimeter test results demonstrated that the peak heat release rate, total heat release, and total smoke release values of the ABS/MFAHP composites were significantly decreased. Digital photos and scanning electron microscopy images of the residues of ABS/25 wt % MFAHP2 composites exhibited compact char layer structures, with many cobweb‐like nanoparticle arrangements formed on the surface by the burning process. The investigation of flame‐retardant mechanisms of ABS/MFAHP composites using infrared spectroscopy and energy‐dispersive X‐ray spectroscopy indicated that both the formation of char residue in the condensed phase and the release of inert gases by the MF shell in the gas phase led to the formation of compact and stable char layers containing carbon/pyrophosphate and aluminum polyphosphate, consequently leading to the good flame‐retardant performance of MFAHP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45008. 相似文献
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Paper-sludge/phenolic composites were fabricated using a novolac-type phenolic resin and paper sludge. A phosphate flame retardant containing halogen (tris 2-chloroethyl phosphate) and inorganic flame retardant (aluminum trihydroxide) were introduced into neat phenolics and paper-sludge/phenolic composite in order to improve their flame retardancy. In addition, magnesium hydroxide and halogenated flame retardant were added into the paper-sludge/phenolic composite. The flame retardancies were estimated with the UL 94 test. To study the flame retardant mechanism, thermal analysis of the phenolics and the paper-sludge/phenolic composites were carried out using a thermogravimetric analyzer and a differential scanning calorimeter. The phosphated flame retardant and inorganic flame retardant both showed the flame retardant effect on the phenolics. However, the flame retardancy of the paper-sludge/phenolic composite was enhanced only by phosphated and halogenated flame retardants. This result is attributed to the fact that the flame retardancies of the phenolics and paper-sludge/phenolic composite depend on their heat capacities and decomposition behaviors. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2043–2050, 1998 相似文献
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The composites based on ethylene–propylene–diene monomer rubber (EPDM) with aluminum hydroxide (ATH), nanoclay, vulcanizing agent, and curing accelerator were prepared by conventional mill compounding method. The thermal stability and the flame retardant properties were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 test, cone calorimeter, and smoke density chamber tests. The results indicated that the substitution of the nanoclay in the EPDM/ATH composites increased the 50% weight loss temperature and the LOI value, and reduced the peak heat release rate (pk‐HRR), the extinction coefficient (Ext Coef), the maximal smoke density (Dm), and the whole smoke at the first 4 min (VOF4) of the test specimens. The synergistic flame retardancy of the nanoclay with ATH in EPDM matrix could imply that the formation of a reinforced char/nanoclay layer during combustion prevents the diffusion of the oxygen and the decomposed organic volatiles in the flame. The mechanical properties of the composites have been increased by replacing more of the nanoclays into the EPDM/ATH blends. The best loading of the nanoclay in EPDM/ATH composites is 3 wt %, which keeps LOI in the enough value, the V‐0 rating in the UL‐94 test, and the improved mechanical properties with better dispersion and exfoliation of the nanoclays shown by transmission electron microscopy (TEM) micrographs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2042–2048, 2013 相似文献
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A low-melting organic-inorganic glass with a high molecular weight soluble in solvents was synthesized by hydrolytic polycondensation of phenyltriethoxysilane followed by a subsequent heat treatment. Softening point and thermostability were strongly increased after heat treatment. The composites of glass/epoxy and glass/clay/epoxy were studied with respect to their thermal properties, fire behavior and mechanical properties. Heat release rate as measured by cone calorimetry was remarkably reduced in the presence of glass, relative to neat epoxy resin and polymer/clay composites. The combination of glass and clay is a promising approach. It showed mainly superposition and even synergistic effects in some fire properties for higher filler concentrations due to the formation of an enhanced barrier. The structure of residue was investigated by transmission electron microscopy (TEM). 相似文献
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以双三羟甲基丙烷为原料合成一种新型含磷阻燃剂,该阻燃剂分子量较大,具有稳定的环状结构,热稳定性高于常用阻燃剂,阻燃效果好。探讨了原料配比、反应温度、反应时间对产率的影响,考察了目标产物的热稳定性能及其对不同织物的阻燃效果,用傅里叶变换红外光谱仪表征了中间体及目标产物的结构。结果表明,当原料配比为1∶3时,磷化温度为50℃,磷化时间5h,胺化温度为75℃时,反应效果较好,收率可达90%以上。目标产物对于锦纶的阻燃效果比较明显,对涤纶、棉有一定的阻燃效果,对于混纺、腈纶阻燃效果不明显。 相似文献
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Preparation of alginate flame retardant containing P and Si and its flame retardancy in epoxy resin
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In the present paper, a novel biomass flame retardant based on alginic acid was synthesized through chemical combination with a reactive P–Si compound. Compared with alginates, the modified alginate showed obviously increased thermal stability and water resisting property, as well as better compatibility with epoxy resin, which can satisfy the requirements of a flame‐retardant additive in the polymer. The flame‐retardant properties were evaluated by vertical burning tests, limiting oxygen index, and microscale combustion calorimetry. Due to the self‐charring capacity of alginate combined with the charring catalyst from P and the charring reinforcer from Si, the modified alginate exhibited much better flame retardancy, taking advantage of the formation of a more continuous, denser, and strengthened char layer than either individual alginate or P–Si flame retardant. The corresponding flame‐retardant mechanisms were investigated and discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45552. 相似文献
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Ceramifiable polyolefin materials protect circuits by forming compact ceramic layers under fire conditions, and can have an excellent application prospect in the refractory cable field. In this paper, Aluminum hypophosphite (AHP) and zinc borate (ZB) were added to further improve flame retardancy and ceramifiable properties of polyethylene (PE)/silicon powder (SP)/wollastonite (WS)/glass frits (GF) composites. The LOI values of composites with AHP/ZB can reach 23.5%, significantly higher than that of PE/SP/WS/GF composites (19.6%). The thermal stability behavior and char yield behaviors of composites could also be characterized by the TG test. The incorporation of AHP/ZB enhances the flexural strength of residue formed at 1000°C from 0.1 to 20.5 MPa. In addition, a new crystal is formed at high temperatures and is identified as the calcium aluminum phosphate phase [CAP, Ca9Al (PO4)7] by XRD analysis. The flow of molten ZB accelerates the reaction of AHP and WS, and this eutectic reaction promotes the formation and stability of ceramics. Furthermore, the SEM analysis reveals the fluxing effect of ZB at low temperatures and AHP at high temperatures. The incorporation of AHP/ZB with a ratio of 1:1 could effectively avoid the vitrification of ceramics and improve their dimensional stability. 相似文献
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Polylactide (PLA) has been getting lots of interests in step with global concerns on sustainable green technology because it is biodegradable with reasonable mechanical strength and can be processed quite easily. But, to compete with commodity polymers in the market PLA‐based green composites need to have higher mechanical and thermal properties. Therefore, in this study, cellulose nanowhiskers (CNWs) as well as nanoclay were used as nanofillers to improve physical properties of PLA. CNWs were prepared from microcrystalline cellulose (MCC) powder by acid hydrolysis, and confirmed by TEM. To improve interfacial bonding between PLA and CNWs maleic anhydride‐grafted PLA (MAPLA) was prepared and used as a compatibilizer. PLA‐based composites were prepared by melt mixing followed by compression molding. Mechanical properties of the composites were measured by UTM and DMA. The melt mixing conditions were optimized first, and then composition was optimized step by step to obtain a PLA‐based green composite with excellent physical properties. CNWs were much better than MCC powder as reinforcing natural fillers. MAPLA and nanoclay could improve considerably physical properties of the PLA‐based composites. Compared to the PLA/MCC composite the tensile strength of the PLA/CNW/MAPLA/nanoclay composite was almost doubled and the glass transition temperature of the composite was 23°C higher, making the composite possible for commercial applications. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers 相似文献