聚氨酯泡沫塑料的阻燃及热解性能

采用热重分析仪、傅里叶变换红外光谱仪和扫描电子显微镜研究了氨基树脂型高分子膨胀阻燃剂（AIFR）阻燃软质聚氨酯泡沫塑料（FPUF）的阻燃、热解性能。结果表明,w（AIFR）为15％以上时,阻燃FPUF的垂直燃烧性能达到美国联邦航空局颁布的条例FAR25．853的要求。AIFR阻燃FPUF热解首先发生脱磷酸、酸催化FPUF脱水和重排交联炭化反应,使其热解中间产物热稳定性增加,热失重速率降低0．144％／s,剩炭率提高10．6％,AIFR主要以凝聚相成炭作用模式起阻燃作用。残炭扫描电子显微镜照片显示,AIFR阻燃FPUF的炭层致密,空洞少;残炭的韧性好．强度较高,可阻挡燃烧过程中的热量和气体的交换,达到阻燃目的。     

超细硼酸锌对LDPE/IFR体系热稳定性的影响

采用热重-差热联机分析和傅里叶变换红外光谱研究了超细硼酸锌(UZB)对膨胀型阻燃剂阻燃低密度聚乙烯的热降解过程的影响。结果表明:UZB对膨胀阻燃低密度聚乙烯体系具有明显的热稳定作用,可使体系起始热失重温度提高,并且显著增加残炭量。差热分析结果表明,UZB可进一步降低膨胀阻燃低密度聚乙烯体系热分解的放热量,降低热降解速度;红外光谱分析表明,UZB与膨胀型阻燃剂阻燃低密度聚乙烯复合体系热解残余物具有芳烃结构的类石墨炭层及含P-O-P、P-O-C、B-B的复杂炭层结构,对内部基材具有良好的高温保护作用。     

含季戊四醇二磷酸酯三聚氰胺-尿醛树脂盐环氧树脂的阻燃性能

合成了一种新型廉价高分子膨胀阻燃剂?季戊四醇二磷酸酯三聚氰胺-尿醛树脂盐. 红外光谱表明,该阻燃剂的结构为双环笼状含磷大分子. 将其应用于环氧树脂,所得阻燃环氧树脂采用热重分析、锥形量热仪研究其热解、阻燃性能,并用Broido方程计算热解活化能的变化. 结果表明,阻燃环氧树脂的平均热释放速率降低30.7%,总热释放量降低52.2%,烟气排放量降低42.7%,CO产率降低70.5%,CO2产率降低73.5%,剩炭率增加19.1%,添加30%的阻燃剂可使材料氧指数达30.5,阻燃效果与DOPO类似. 环氧树脂热解活化能为73.5 kJ/mol,添加阻燃剂后其值为83.5 kJ/mol,降低10 kJ/mol,表明阻燃剂对环氧树脂的热解具有催化成炭作用.     

用反相悬浮聚合法制备膨胀型阻燃剂及其在丁苯橡胶中的应用

采用反相悬浮法聚合丙烯酸钠,同时将化学膨胀阻燃体系(IFR)三组分聚磷酸铵、季戊四醇和三聚氰胺加入到聚合体系中进行原位包裹,用傅里叶变换红外光谱对聚合产物的结构进行了表征,研究了三聚氰胺用量和聚磷酸铵与季戊四醇配比对丁苯橡胶硫化胶阻燃效果的影响,采用热重法分析了阻燃丁苯橡胶的热性能,并通过扫描电镜观察了添加IFR的丁苯橡胶在燃烧后表面的微观形态。结果表明,三聚氰胺的质量分数为IFR体系的3.0%、聚磷酸铵与季戊四醇的质量比为4.00～5.67时IFR体系的剩炭率最高,阻燃性能较好;添加IFR后丁苯橡胶的阻燃性能得到相应改善,当IFR质量分数为30%时丁苯橡胶硫化胶的极限氧指数可达27.5%;添加了IFR的丁苯橡胶硫化胶在燃烧时形成了较为致密的泡沫炭层,表明IFR对丁苯橡胶具有较好的膨胀阻燃效果。     

聚丙烯/低温可膨胀石墨阻燃复合材料的性能研究

采用低温可膨胀石墨(LTEG)作为阻燃剂,制备了聚丙烯基阻燃复合材料。研究了聚丙烯/LTEG阻燃复合材料的阻燃性能、热性能、剩炭结构和力学性能。研究发现,采用LTEG为阻燃剂的聚丙烯基阻燃复合材料具有优异的阻燃性能,LTEG质量分数为15%时,复合材料氧指数已达27%。聚丙烯/LTEG复合材料的热失重温度低,在燃烧过程中并没有形成理想致密的炭层。LTEG对聚丙烯具有增强作用,随着其用量的增加,复合材料的拉伸强度增加,断裂伸长率不断下降。     

膨胀阻燃聚乙烯的研究

将可膨胀石墨（EG）和传统的膨胀阻燃剂（IFR）用于制备膨胀阻燃聚乙烯（PE）,采用极限氧指数对其阻燃性能进行了研究,探讨了2种阻燃剂之间的协同阻燃作用,并采用差示扫描量热仪和红外光谱对其热降解过程和炭层结构分别进行了分析。结果表明,EG和IFR对PE具有很好的协同阻燃作用,当其配比为1:1时,膨胀阻燃PE可获得较佳的阻燃性能,阻燃剂用量仅为30份就可使膨胀阻燃PE的极限氧指数达到31.5 %,远高于单一阻燃体系;在热降解过程中,复合膨胀阻燃体系仍表现出EG和IFR的特征降解过程,热降解成炭由二者的热降解产物构成,证实了二者之间的物理作用机理,物理膨胀炭层和化学膨胀炭层的结合有效增加了炭层的隔热、隔氧作用,有利于阻燃性能的改善。     

膨胀型无卤阻燃环氧树脂的制备及性能

采用新型磷系阻燃剂(FR)与聚磷酸铵组成的膨胀型阻燃剂(IFR)制备了膨胀型无卤阻燃环氧树脂(EP)材料.通过氧指数、热失重和扫描电镜等研究IFR对环氧树脂的阻燃性能、热降解行为及微观结构的影响.结果表明:加入IFR使材料的阻燃性能明显提高,IFR/EP的氧指数达到37.6%.600℃时IFR/EP的残炭量较纯EP从21.24%增至43.08%.扫描电镜观察发现.经IFR阻燃的EP在燃烧时形成了由封闭孔洞构成的均匀闭孔结构炭层,表明IFR对EP材料具有良好的膨胀阻燃效果.     

竹基多孔碳协同二乙基次膦酸铝催化阻燃环氧树脂及作用机理研究

利用可再生资源为协效剂,将竹基多孔碳（PCM）与二乙基次膦酸铝（AlPi）添加于环氧树脂（EP）,研究了PCM协同AlPi催化阻燃EP复合材料性能及作用机理。结果表明,PCM(3%)与AlPi(4.4%)复合于EP后,复合材料的极限氧指数（LOI）由纯EP的24.6%提高到42.6%,UL 94测试达到V-0级,热释放速率峰值降低60.7%,PCM协同AlPi催化阻燃EP的效果显著。热失重-红外光谱联用、热失重-质谱联用、X射线光电子能谱及拉曼光谱研究揭示,PCM具有催化AlPi在气相释放二乙基次膦酸捕捉自由基,在凝聚相形成氧化铝、磷酸铝和焦磷酸铝,提高炭层的耐热氧化能力及促进类石墨炭层形成的作用。     

DOPO改性ATH阻燃环氧树脂性能的研究

采用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)改性氢氧化铝(ATH),制备了(DOPO-ATH)阻燃剂,并用以阻燃环氧树脂(EP)。利用傅里叶红外光谱(FTIR)、热失重分析(TGA)、对DOPO-ATH进行了结构表征和热分析。通过锥形量热测试(CCT)、扫描电子显微镜(SEM)、热重红外联用(TG-FTIR)等手段对EP/DOPO-ATH复合材料的阻燃性能及残炭结构进行研究。结果表明,DOPO-ATH的残炭率(700℃)高达68%,具有较好的成炭能力。与纯EP相比,7%DOPO-ATH使EP的热释放速率峰值(pHRR)下降到689.5kW/m~2,相比纯EP的pHRR(1079.2kW/m~2)下降了36%。随DOPO-ATH含量的增加,EP/DOPO-ATH的残炭率逐渐增加,EP/DOPO-ATH燃烧炭层致密,炭层中以含磷和铝的化合物为主,形成了良好的凝聚相阻燃机理,同时DOPO-ATH在气态阶段磷的释放对EP固化物的火焰抑制作用,实现气相阻燃机理。     

用于环氧树脂磷-氮阻燃固化剂的合成及应用

以1,2-环己二胺(DACH)和苯基膦酰二氯(PPDC)为原料合成了一种新型环氧树脂(EP)阻燃固化剂苯基膦酰-1,2-环己二胺(PPDAC),并用傅里叶变换红外光谱(FTIR)、氢核磁共振(~1HNMR)和热重分析仪(TGA)对其进行了表征,制备了系列PPDAC/EP,采用TGA、极限氧指数(LOI)、垂直燃烧试验和扫描电镜(SEM)研究了其热稳定性、阻燃性和炭层形貌。结果表明:PPDAC的填充可以提高EP树脂的阻燃性能,添加PPDAC的EP残炭率和阻燃性均得到提高,但其初始分解温度和力学性能下降。添加PPDAC的EP残炭表面发泡膨胀明显,阻燃效果优异。     

膨胀型阻燃剂阻燃环氧树脂的阻燃性能及影响因素

研究了季戊四醇磷酸酯三聚氰胺盐微胶囊化的多聚磷酸铵（KDIFR）、三聚氰胺-甲醛树脂微胶囊化的多聚磷酸铵（MAPP）和多聚磷酸铵（APP） 3种膨胀型阻燃剂,及引入硼、铝元素对膨胀型阻燃环氧树脂(EP)阻燃性能的影响,采用极限氧指数法和水平燃烧法测试材料的燃烧性能。结果表明,3种阻燃剂中APP的阻燃效果最好,当APP/EP为0.3（质量比,下同）时,其极限氧指数为32.2 %,达到难燃级水平;在EP/APP中引入铝元素或硼元素可使阻燃效果提高,硼、铝共存时阻燃效果更加突出,加入APP总量0.8 %的硼酸铝可使EP/APP的自熄时间由48 s降为24 s;热分析结果表明,APP热分解吸热恰与EP的热降解产物燃烧放热相匹配,这是使EP/APP的阻燃性能提高的主要原因;在EP/APP中引入硼和铝元素可明显促进EP/APP成炭,起到协同阻燃作用。     

茶皂素基膨胀型阻燃剂的制备及其在涂料中的应用

采用多羟基、多羧基的活性天然产物茶皂素为原料,与聚磷酸铵和季戊四醇在一定条件下反应,制备一种聚磷酸酯类茶皂素基三位一体新型环保膨胀型阻燃剂。采用傅里叶红外分析技术对阻燃剂进行了结构表征,采用综合热分析仪对阻燃剂的热降解性能进行了研究。结果表明,茶皂素与聚磷酸铵、季戊四醇发生反应,生成聚磷酸酯类茶皂素基膨胀型阻燃剂,且该阻燃剂具有良好的热稳定性,降解热释放较小,高温残留率高,最终的质量残留率高达30.77%。将制备阻燃剂用于阻燃涂料中,并采用氧指数测试仪和锥形量热仪研究了阻燃涂料的阻燃性能和热解性能。研究表明,茶皂素基三位一体膨胀型阻燃剂能显著提高涂料的阻燃性能,阻燃涂料的氧指数值高达34.2%,耐火时间为11.1 min,且锥形量热实验中,该阻燃涂料试样的平均热释放速率（m-HRR）为36.18 kW/m2,总热释放量（THR）为5.25 kJ/m2,平均有效燃烧热（m-EHC）为5.11 kJ/kg,与含复合型阻燃剂的阻燃涂料试样相比,阻燃性能得到极大提高。该制备阻燃剂不含卤素,集三源一体,具有阻燃性能优越,相容性能良好,高效环保等优点。     

An efficient approach to improving fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene composites via incorporating organo‐modified sepiolite

In this work, an efficient approach to improving the fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene (PP) composites is developed via incorporating functionalized sepiolite (organo‐modified sepiolite [ONSep]). The PP composites with different amounts of intumescent flame retardants and ONSep were prepared by melt compounding. The morphology, thermal behavior, fire retardancy, smoke suppression, and mechanical property of flame‐retardant PP composites were studied. The results indicate an appropriate amount of ONSep in the flame‐retardant PP composites can increase thermal degradation temperature and char formation as well as a reduction of the peak heat release rate and total heat release; moreover, the addition of ONSep significantly decreases the CO production, total smoke production, smoke production rate, and smoke temperature. Simultaneously, the impact strength of intumescent flame‐retardant PP composite is also maintained by introducing an appropriate amount of ONSep as compared with that without ONSep.     

Intumescent char structures and flame‐retardant mechanism of expandable graphite‐based halogen‐free flame‐retardant linear low density polyethylene blends

The structures of the intumescent charred layers formed from expandable graphite (EG)‐based intumescent halogen‐free flame retardant (HFFR) linear low‐density polyethylene (LLDPE) blends and their flame‐retardant mechanism in the condensed phase have been studied by dynamic Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), laser Raman spectroscopy (LRS), scanning electron microscopy (SEM), differential thermal analysis (DTA) and thermal conductivity (TC) measurements. The dynamic FTIR, XPS and LRS data show that the carbonaceous structures of intumescent charred layers consist of EG and various numbers of condensed benzene rings and/or phosphocarbonaceous complexes attached by the P? O? C and P? N bonds or quaternary nitrogen products. The addition of EG can hasten the formation of these phosphocarbonaceous structures. The above results show that the flame‐retardant mechanism in the condensed phase is that the compact char structures, as observed by SEM, slow down heat and mass transfer between the gas and condensed phase and prevent the underlying polymeric substrate from further attack by heat flux in a flame. The DTA and TC data show that carbonaceous charred layers are good heat‐insulating materials, the TC value of which is only about one‐tenth of that of the corresponding blend and that they increase the oxidization temperature and decrease thermal oxidization heat of the LLDPE/EG/HFFR systems. © 2003 Society of Chemical Industry     

无卤阻燃聚乙烯醇缩甲醛纤维的制备与表征

以新戊二醇和三氯硫磷为原料,一步法合成了无卤膨胀型阻燃剂二硫代焦磷酸双新戊二醇酯(BGDTP);采用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(~1H-NMR)对BGDTP的结构进行了表征。将BGDTP添加到聚乙烯醇(PVA)中进行共混纺丝,制备了阻燃聚乙烯醇缩甲醛(PVFM)纤维,并对其力学性能、阻燃性能和热性能进行了表征。结果表明:一步法合成BGDTP的收率为82%;随着纤维中BGDTP添加量的增加,PVFM纤维的极限氧指数(LOI)、高温下的最大分解速率温度和残炭量均增大,但其断裂强度略有下降;当w(BGDTP)为20%时,阻燃PVFM纤维的LOI为30.8%,断裂强度为5.42 cN/dtex,最大热分解温度和残炭率比纯PVFM纤维均有较大幅度增加,燃烧形成连续致密的膨胀炭层。     

Thermal degradation behaviors and flame retardancy of epoxy resins with novel silicon‐containing flame retardant

A novel macromolecular silicon‐containing intumescent flame retardants (Si‐IFR) was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus‐silicon characterized by IR. Epoxy resins (EP) were modified with Si‐IFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). Twenty percentage of weight of Si‐IFR was doped into EP to get 27.5% of LOI and UL 94 V‐0. The degradation behavior of the flame retardant EP was studied by thermogravimetry, differential thermogravimetry, scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. The experimental results exhibited that when EP/Si‐IFR was heated, the phosphorus‐containing groups firstly decompose to hydrate the char source‐containing groups to form a continuous and protective carbonaceous char, which changed into heat‐resistant swollen char by gaseous products from the nitrogen‐containing groups. Meanwhile, SiO₂ reacts with phosphate to yield silicophosphate, which stabilizes the swollen char. The barrier properties and thermal stability of the swollen char are most effective in resisting the transport of heat and mass to improve the flame retardancy and thermal stability of EP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Application of a novel halogen‐free intumescent flame retardant for acrylonitrile‐butadiene‐styrene

A novel intumescent flame retardant (IFR), containing ammonium polyphosphate (APP) and poly(tetramethylene terephthalamide) (PA4T), was prepared to flame‐retard acrylonitrile‐butadiene‐styrene (ABS). The flame retardation of the IFR/ABS composite was characterized by limiting oxygen index (LOI) and UL‐94 test. Thermogravimetric analysis (TGA) and TGA coupled with Fourier transform infrared spectroscopy (TG‐FTIR) were carried out to study the thermal degradation behavior of the composite and look for the mechanism of the flame‐retarded action. The morphology of the char obtained after combustion of the composite was studied by scanning electron microscopy (SEM). It has been found the intumescent flame retardant showed good flame retardancy, with the LOI value of the PA4T/APP/ABS (7.5/22.5/70) system increasing from 18.5 to 30% and passing UL‐94 V‐1 rating. Meanwhile, the TGA and TG‐FTIR work indicated that PA4T could be effective as a carbonization agent and there was some reaction between PA4T and APP, leading to some crosslinked and high temperature stable material formed, which probably effectively promoted the flame retardancy of ABS. Moreover, it was revealed that uniform and compact intumescent char layer was formed after combustion of the intumescent flame‐retarded ABS composite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of gas-condensed phase synergistic system of 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide and polydopamine on flame retardancy of epoxy resin

Polydopamine (PDA) was prepared by using dopamine which has good charring ability. The PDA was used as an environmentally friendly flame retardant and combined with 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) to improve the flame retardancy of epoxy (EP) resin. The flame retardancy and thermal stability of EP composites were researched by UL-94 vertical burning, limiting oxygen index (LOI), cone calorimetry tests, and thermal gravimetric analyzer. Adding DOPO alone requires 6% to make EP obtain the UL-94 V0. If DOPO and PDA are combined, only 4% is needed to make EP obtain the UL-94 V0, which suggests that there is good synergistic effect between them. Moreover, the peak of heat release rate of EP/DOPO/PDA composites is less than that of EP/DOPO composites. The reactions among EP, DOPO, and PDA reduce the release of combustible gases at the early stage of degradation; at the same time, DOPO volatilize to the gas phase, quench the free radicals, and the combustion can be stopped. In addition, due to the decrease of the amount of PDA/DOPO, the EP composite can get a higher glass transition temperature, but due to the aggregation of PDA in EP, the tensile property of EP composite decreases.     

Thermal degradation behavior and gas phase flame‐retardant mechanism of polylactide/PCPP blends

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 (E_a) of neat PLA and PLA/15% PCPP blend were calculated via the Flynn–Wall–Ozawa method. The E_a 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.     

A new intumescent flame retardant containing phosphorus and nitrogen: Preparation,thermal properties and application to UV curable coating

A novel intumescent flame retardant piperazine-N,N′-bis(acryloxyethylaryl-phosphoramidate) (N-PBAAP) containing phosphorus and nitrogen used for UV curable coating was synthesized and characterized by Fourier transform infrared spectrometry (FTIR), ¹H and ³¹P nuclear magnetic resonances (NMRs). The thermal degradation and volatilized products of the N-PBAAP cured film were monitored by real time Fourier transform infrared (RT-FTIR) and thermal gravimetric-Fourier transform infrared (TG-FTIR) technique, respectively. Scanning electron microscopy (SEM) was employed to investigate the surface morphology of the residual char. And possible mechanism for the thermal degradation of N-PBAAP film was proposed. To investigate the flame retardancy of N-PBAAP in UV curable coatings, a series of UV curable intumescent flame retardant resins were obtained by blending N-PBAAP with EA (epoxy acrylate oligomer) in different ratios. The flammability and thermal properties of the cured films were studied by Microscale Combustion Calorimeter (MCC) and thermogravimetric analysis (TGA). In MCC test, the peak heat release rates (pHRRs) of the blends were all lowered by the addition of N-PBAAP comparing with the pure EA. And TG results revealed that N-PBAAP can greatly enhance the char residues of EA films at high temperature region.