三聚氰胺聚磷酸盐/季戊四醇配比、协效剂组及表面改性对聚丙烯基木塑复合材料的膨胀阻燃影响

通过极限氧指数(LOI)、线性燃烧速率(LBR)、热重分析和锥形量热分析等技术手段研究膨胀型阻燃剂(IFRs)中三聚氰胺聚磷酸盐(MPP)和季戊四醇(PER)的质量比、组成为m(MgO):m(可膨胀石墨,EG):m(SiO₂)=1:5:5的协效剂组(MgO/EG/SiO₂)和硅烷偶联剂(KH550)对聚丙烯基木塑复合材料(WPC)阻燃性能的影响。 结果表明,当IFRs中m(MPP):m(PER)=23:2(IFRs-M1)、质量分数为25%时的阻燃性能最佳,膨胀阻燃复合材料WPC/IFRs-M1的LOI和LBR分别为27.1%和3.89 mm/min,较未添加的WPC分别提高48.1%和下降89.79%,燃烧时的热释放速率、总热释放量、总烟释放量和CO₂释放量分别降低了76.2%、50.1%、6.9%和65.4%,600 ℃时的残炭率提高了498.3%。 协效剂组和KH550表面处理均可进一步改善WPC/IFRs-M1的阻燃性能,均对IFRs-M1具有良好的阻燃增效作用。 相比于WPC/IFRs-M1,同时用这两种阻燃增效手段的WPC/IFRs-M1/MgO/EG/SiO₂/KH550,其LOI提高了3.7%,LBR降低了20.3%;材料的热稳定性明显提高,热失重降低;燃烧时的热释放速率、总热释放量、总烟释放量和CO₂释放量分别降低了36.5%、37.6%、57.5%和33.33%,600 ℃时的残炭率提高了84.02%,显示出二者更好的协同效应。     

协效阻燃聚丙烯的阻燃性能

本文研究了以聚磷酸铵(APP)为主阻燃剂,次磷酸铝(AHP)和三聚氰胺氰尿酸盐(MCA)为辅阻燃剂的协效阻燃体系对聚丙烯(PP)阻燃性能的影响。 采用垂直燃烧测试、极限氧指数(LOI)测试、热重分析、锥形量热仪测试、扫描电子显微镜分析等技术手段对所制备的阻燃样品进行了阻燃性能分析。 结果表明:单独添加任一质量分数30%阻燃剂,均不能使PP获得良好的阻燃性能;当阻燃剂总质量分数保持在30%,m(APP)：m(AHP)：m(MCA)=4：1：1时获得理想阻燃效果,此时阻燃PP的LOI为33%,垂直燃烧测试达到V-0级,热释放速率峰值(PHRR)从765.7 kW/m²降为122.7 kW/m²。     

基于次磷酸铝的聚丙烯木塑复合材料的阻燃改性研究

本研究以次磷酸铝(AP)为阻燃剂,探讨了其对聚丙烯/木粉复合材料(WPC)的阻燃性能的影响,并阐明了相关的阻燃机理。实验结果证明,当AP的添加量为30 wt%时,可以使木粉含量为30 wt%的WPC通过垂直燃烧V-0级,氧指数达到25. 0%。锥形量热测试结果表明:AP的加入能够有效抑制复合材料的燃烧,30wt%AP的加入能够使木粉含量为30 wt%的WPC的热释放峰值(PHRR)降低至240 k W/m~2,与不含阻燃剂的WPC相比降低了50%;燃烧后所得的残炭的质量高达45. 2%。扫描电子显微镜(SEM),热重-红外联用(TGFTIR)和X射线光电子能谱结果表明:添加AP后,燃烧过程中WPC/AP的气相产物中会有水、二氧化碳及含PO_2-结构的物质等生成,从而赋予WPC/AP气相阻燃作用;此外,WPC/AP在燃烧中能够热解生成内外结构不同的炭层,内部炭层主要为含铝为主的交联稳定炭层,而外部炭层主要含有交联P-O-C结构等,因此,AP能够同时通过气相和凝聚相的双重作用实现WPC的高效阻燃。     

OMMT-NC-膨胀型阻燃剂三元协同阻燃LLDPE的效果

采用有机蒙脱土(OMMT)和碳酸镍(NC)为阻燃协效剂,与膨胀型阻燃剂(IFR)三元体系协同阻燃线性低密度聚乙烯(LLDPE).采用热重分析(TGA)、氧指数(LOI)测试、UL-94燃烧测试和锥形量热测试(CONE)研究了LLDPE阻燃体系的热稳定性和燃烧性能;采用红外光谱分析(FT-IR)、数码相机和扫描电子显微镜(SEM)对燃烧残余物的结构和形貌进行了分析.结果表明:固定mnLLDPE/mIFR=7/3,当moMMT/m(LLDPE+IFR)=0.04时,阻燃体系的LOI为31.5％,通过UL-94 V-0级测试,LLDPE-IFR-OMMT的残炭率为15.09％,最大热释放速率(PHRR)相比于纯LLDPE降低了50％;向LLDPE-IFR-OMMT体系中添加NC,少量的NC就能显著增加体系的阻燃性能,当mNC/m(LLDPE+IFR)=0.02时,阻燃体系的LOI为32.7％,LLDPE-IFR-OMMT-NC的残炭率达到19.04％,PHRR相比于纯LLDPE降低了57％.OMMT和NC的加入能催化LLDPE-IFR成炭,形成致密的炭层,增加炭层的强度,从而提高复合材料的阻燃性能.     

改性纳米二氧化硅在环氧树脂膨胀阻燃体系中的协效作用研究

以膨胀阻燃剂(IFR)为主要阻燃剂,以纳米二氧化硅(Nano-SiO_2)及KH570改性纳米二氧化硅(SiO_2-gKH570)为协效剂制备阻燃环氧树脂(EP)材料,对比研究了2种EP/IFR/SiO_2及EP/IFR/SiO_2-g-KH570体系材料的阻燃性能、力学性能、热量释放、烟气释放、热降解行为及炭层表面形貌。结果表明,当阻燃剂的总添加量为环氧树脂基体质量分数的30%(SiO_2为IFR质量的10%)时,SiO_2与IFR具有阻燃协同效应,在同样的添加比例下,改性的SiO_2会增强这种协同作用。EP/IFR/SiO_2-g-KH570体系与EP/IFR/SiO_2体系相比,两者氧指数(LOI)分别为30.2%和28.6%,UL-94测试分别通过V-0和V-1级; EP/IFR/SiO_2-g-KH570的力学性能较EP/IFR/SiO_2也有所提高,弯曲强度和抗冲击强度分别提高了10.2MPa和0.6KJ·m~(-2);锥形量热及热分析结果表明,EP/IFR/SiO_2-g-KH570体系在热释放、CO和CO_2释放指标上数值明显降低,热稳定性增加;残炭的电镜形貌分析表明,EP/IFR/SiO_2-g-KH570体系能形成更加致密和连续的炭层,能起到很好的物理屏障作用,显示出较好的阻燃效果。     

可膨胀石墨阻燃体系在聚丙烯中的作用

采用可膨胀石墨(EG)为主阻燃剂,包裹红磷(MRP)为阻燃协效剂制备阻燃聚丙烯(PP)。在mEG∶mMRP≥2时,阻燃效果最佳。阻燃剂(FR)含量达到30%后,阻燃效果大幅度提高,氧指数大于28。采用热失重和流变学方法分析了炭层质量,探讨了在mEG∶mMRP≥2时,阻燃效率最高的原因。相容剂马来酸酐接枝聚丙烯(PP-g-MAH)能够改善阻燃剂和聚丙烯之间的相容性,提高粘结力,改善炭层质量,提高材料的氧指数,PP-g-MAH用量为30%时,材料的氧指数达到31.4。     

膨胀型阻燃UPR复合材料的阻燃及抑烟性能

将叶蜡石(PYR)与膨胀型阻燃剂[IFR,聚磷酸铵(APP)/季戊四醇(PER)/三聚氰胺(Mel))复配],应用于不饱和聚酯树脂(UPR),得到膨胀型阻燃UPR复合材料。通过氧指数(LOI)、垂直燃烧(UL94)、烟密度等级(SDR)、热分析(DSC-TG)对阻燃复合材料的阻燃、抑烟及热稳定性能进行了研究。结果表明:在该膨胀型复配阻燃体系中,叶蜡石与IFR存在明显的协效作用,在mPYR∶mAPP∶mPER∶mMel=4∶2∶1∶1,复合阻燃剂的含量为40%的情况下,LOI高达36.4,阻燃级别为UL94 V-0级,SDR为62.95,满足国家对B1级电器类热固性塑料的使用要求。     

聚磷腈微球的制备及其阻燃PET的研究

采用沉淀聚合法制备聚环三磷腈-co-(3,4-二羟基苯甲酸)(Poly(HCCP-co-PCA))微球,通过傅里叶变换红外光谱、扫描电镜和热重分析等测试手段对其进行表征,研究单体摩尔比对微球的结构、微观形貌以及热稳定性的影响,其中n(HCCP)/n(PCA)为1/0.5时,聚磷腈微球的粒径较为均一,分散均匀,直径为1.5μm左右,并且具有优异的热稳定性和成炭性能。采用熔融共混法制备PET/Poly(HCCP-co-PCA)复合材料,研究Poly(HCCP-co-PCA)的用量对复合材料阻燃性能的影响,并探究其阻燃机理。结果表明,随着Poly(HCCP-co-PCA)含量的增加,复合材料的阻燃性能明显提高。当Poly(HCCP-co-PCA)添加量为1.5(wt)%时,复合材料通过UL 94-V0等级测试,极限氧指数为28.8%,并且热释放速率峰值和总热释放量分别降低了75.26%和69.07%。其阻燃原理主要是燃烧时生成炭层较多,起到较好隔绝效果,同时产生不可燃气体,进一步提升阻燃效果。     

季膦萘磺酸盐离子液体与甲基膦酸二甲酯协同阻燃环氧树脂

合成了一种新型季膦萘磺酸盐室温离子液体[TBP]NS,利用傅里叶变换红外光谱(FTIR)和核磁共振波谱(1H NMR和31P NMR)确定了其结构,并将其与甲基膦酸二甲酯(DMMP)复配用于制备阻燃环氧树脂.阻燃性能测试结果表明,当在环氧树脂(EP)中加入质量分数为6%的[TBP]NS和4%的DMMP时,所得阻燃环氧树脂EP/4%[TBP]NS/6%DMMP的极限氧指数达到31.2%, UL-94垂直燃烧通过V-0级别.与纯环氧树脂相比,该阻燃环氧树脂的峰值热释放速率(PHRR)降低了59%,总热释放(THR)降低了43%,峰值CO释放速率(PCOP)降低了41%,残炭率升高了97%.[TBP]NS和DMMP在氧指数、垂直燃烧和锥形量热测试中均展现出优异的协同阻燃作用,并且表现出良好的炭化能力和降热效果.在力学性能方面,与单纯加入DMMP的环氧树脂相比,EP/4%[TBP]NS/6%DMMP的拉伸强度、断裂伸长率和弯曲强度均有提高.     

高密度聚乙烯/蒙脱土纳米复合材料膨胀阻燃体系的性能

使用以乙烯/醋酸乙烯共聚物(EVA)为相容剂的高密度聚乙烯/蒙脱土(HDPE/OMT)纳米复合材料作为基体,制备了含不同成炭剂的聚磷酸铵(APP)膨胀阻燃体系,对其阻燃性能进行了比较和研究,并分析了蒙脱土与膨胀阻燃剂协效作用的机理。热重分析(TGA)、垂直燃烧(UL-94)、极限氧指数(LOI)、锥形量热计结果表明:APP/季戊四醇(PER)体系熔融过程较短可形成蒙脱土增强炭层;PER/PA/OMT体系中较高的有机物含量有利于蒙脱土迁移和堆积。     

Flame retardant effects of organic inorganic hybrid intumescent flame retardant based on expandable graphite in silicone rubber composites

In this work, an organic inorganic hybrid intumescent flame retardant (functionalized expandable graphite, FEG) was synthesized and characterized by Fourier transform infrared spectrometry (FTIR). The flame retardant effects of FEG in silicone rubber (SR) composites were investigated by cone calorimeter test (CCT), and the thermal stability of SR composites was studied using TGA. The CCT results showed that FEG can effectively reduce the flammable properties including peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), total smoke release (TSR), and smoke factor (SF). An improvement of thermal stability of SR/FEG was also observed. Compared with EG, FEG can further reduce THR, SPR, and TSR of SR/FEG composites in combustion process. Moreover, there is a more obvious intumescent char layer formed from the sample with FEG than the sample with EG at the same loading in SR composites. Copyright © 2014 John Wiley & Sons, Ltd.     

Thermal and flame retardant properties of novel intumescent flame retardant low-density polyethylene (LDPE) composites

A char-forming agent (CFA) and silica-gel-microencapsulated ammonium polyphosphate (MCAPP) were selected to form novel intumescent flame retardant system (IFRs), and then the influence of this novel IFRs on the thermal and flame retardant properties of low-density polyethylene (LDPE) were studied. The results of cone calorimetry show that the flame retardant properties of LDPE with 30?wt% novel IFR (CFA/MCAPP?=?1:3) improve remarkably. The heat release rate peak, total heat release (THR) decreases, respectively, from 1479.6 to 273.5?kW?m^?2 and from 108.0 to 80.5?MJ?m^?2. The LDPE composite with CFA/MCAPP?=?1:3 has the excellent water resistance, and it can still obtain a UL-94?V-0 rating after treated with water at 70?°C for 168?h.     

The study of mechanical behavior and flame retardancy of castor oil phosphate-based rigid polyurethane foam composites containing expanded graphite and triethyl phosphate

The goal of this work was the synthesis of novel flame-retarded polyurethane rigid foam with a high percentage of castor oil phosphate flame-retarded polyol (COFPL) derived from renewable castor oil. Rigid flame-retarded polyurethane foams (PUFs) filled with expandable graphite (EG) and diethyl phosphate (TEP) were fabricated by cast molding. Castor oil phosphate flame-retarded polyol was derived by glycerolysis castor oil (GCO), H₂O₂, diethyl phosphate and catalyst via a three-step synthesis. Mechanical property, morphological characterization, limiting oxygen index (LOI) and thermostability analysis of PUFs were assessed by universal tester, scanning electron microscopy (SEM), oxygen index testing apparatus, cone calorimeter and thermogravimetric analysis (TGA). It has been shown that although the content of P element is only about 3%, the fire retardant incorporated in the castor oil molecule chain increased thermal stability and LOI value of polyurethane foam can reach to 24.3% without any other flame retardant. An increase in flame retardant was accompanied by an increase in EG, TEP and the cooperation of the two. Polyurethane foams synthesized from castor oil phosphate flame-retarded polyol showed higher flame retardancy than that synthesized from GCO. The EG, in addition to the castor oil phosphate, provided excellent flame retardancy. This castor oil phosphate flame-retarded polyol with diethyl phosphate as plasticizer avoided foam destroy by EG, thus improving the mechanical properties. The flame retardancy determined with two different flame-retarded systems COFPL/EG and EG/COFPL/TEP flame-retarded systems revealed increased flame retardancy in polyurethane foams, indicating EG/COFPL or EG/COFPL/TEP systems have a synergistic effect as a common flame retardant in castor oil-based PUFs. This EG/COFPL PUF exhibited a large reduction of peak of heat release rate (PHRR) compared to EG/GCO PUF. The SEM results showed that the incorporation of COFPL and EG allowed the formation of a cohesive and dense char layer, which inhibited the transfer of heat and combustible gas and thus increased the thermal stability of PUF. The enhancement in flame retardancy will expand the application range of COFPL-based polyurethane foam materials.     

Preparation of flame retardant and thermal insulation polystyrene foams via high internal phase emulsion template

Expanded polystyrene foam (EPSF), valued for its excellent insulation properties, faces a significant flammability challenge due to its cellular structure. Traditional flame retardant methods such as physical blending and layer-by-layer assembly have poor applicability to EPSF. Therefore, it is necessary to find other more effective methods for synthesizing flame-retardant EPSF. The high internal phase emulsion (HIPE) template is one of the simplest and most commonly used methods for synthesizing porous materials, which have features such as adjustable pore structures and high porosity. In this work, ammonium polyphosphate (APP)/starch was added to the dispersed phase of the HIPE to prepare the flame-retardant EPSF by one-pot method. The morphology, thermal stability and flame retardancy of the foams were investigated. When the addition of APP/starch (the weight ratio is 1:1) reached 30 wt.%, the peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of the composite foam decreased by 74.7%, 65.9%, and 24.7%, respectively, compared to the pure PS foam. Meanwhile, its limiting oxygen index (LOI) value reached 25.8%, and the UL-94 rating reached V-1 level, indicating significant improvement in flame retardancy. This study provides an effective strategy for synthesizing flame-retardant porous materials.     

Synergistic effect between a char forming agent (CFA) and microencapsulated ammonium polyphosphate on the thermal and flame retardant properties of polypropylene

The synergistic effect between a char forming agent (CFA) and microencapsulated ammonium polyphosphate (MAPP) on the thermal and flame retardancy of polypropylene (PP) are investigated by limiting oxygen index (LOI), UL‐94 test, cone calorimetry, thermogravimetric analysis (TGA), scanning electron micrograph (SEM), and water resistance test. The results of cone calorimetry show that heat release rate peak (PHRR), total heat release (THR), and the mass loss of PP with 30 wt% intumescent flame retardant (IFR, CFA/MAPP = 1:2) decreases remarkably compared with that of pure PP. The HRR, THR, and mass loss decrease, respectively from 1140 to 100 kW/m², from 96 to 16.8 MJ/m², and from 100 to 40%. The PP composite with CFA/MAPP = 1:2 has the best water resistance, and it can still obtain a UL‐94 V‐0 rating after 168 hr soaking in water. Copyright © 2008 John Wiley & Sons, Ltd.     

Flame retardancy and thermal degradation of halogen-free flame-retardant biobased polyurethane composites based on ammonium polyphosphate and aluminium hypophosphite

In this work, based on castor oil (CO), flame retardant polyurethane sealants (FRPUS) with ammonium polyphosphate (APP) and aluminum hypophosphite (AHP) were prepared. The synergistic flame retardant effects between APP and AHP on flame retardancy, thermal stability, and flame retardant mechanisms of FRPUS were investigated. It was found that when the mass ratio of APP and AHP was 5:1, the limiting oxygen index (LOI) value of FRPUS increased to 35.1%, In addition, at this ratio, the parameters from cone calorimeter testing (CCT) were reduced; these parameters include peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP). The thermal decomposition behavior of the FRPUS was investigated by thermogravimetric analysis (TGA). The results showed that AHP improved the thermal stability of the PUS/APP system and increased char residue at high temperatures. Moreover, the residual carbon was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM), gas phase pyrolysis products were investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and thermogravimetric analysis/mass spectrometry (TG-MS). It was observed that the flame retardant mechanisms of the APP/AHP system was the combination of gas and condensed phase flame retardant mechanisms.     

Poly (diallyldimethylammonium) and polyphosphate polyelectrolyte complexes as an all‐in‐one flame retardant for polypropylene

Poly (diallyldimethylammonium chloride) (PDDA) and ammonium polyphosphate (APP) deionized chloride ions and ammonium ions by ionizing in aqueous solution respectively, then combined to form poly (diallyldimethylammonium) and polyphosphate (PAPP) polyelectrolyte complexes as an all‐in‐one flame retardant for polypropylene and its composites were characterized by Fourier transform infrared (FTIR) spectroscopy and X‐ray photoelectron spectroscopy. One flame retardant system composed of PAPP and PP, the other flame retardant system composed of PAPP, Polyamide‐6 (PA6) and PP were tested by limiting oxygen index (LOI), UL‐94, cone calorimeter tests and thermogravimetric analysis (TGA) and compared with pure PP. The results showed that the LOI value of PP/PAPP composite can reach 27.5%, and UL‐94 V‐2 rating can be reached at 25 wt% PAPP loading. Meanwhile the cone calorimetry results displayed that the peak heat release rate (PHRR) and total heat release (THR) were reduced up to 69.3% and 22.5%, respectively, compared with those of pure PP. After adding 5 wt% PA6, the carbon source missing due to the early PAPP decomposition can be made up, and PHRR and THR can be further reduced slightly. The flame retardant mechanism of PAPP was studied by FTIR spectroscopy and X‐ray photoelectron spectroscopy. Six‐membered ring of C─N containing conjugate double bonds, cross‐linked phosphate structure formed stable, intumescent, compact char layer which greatly improved the flame retardancy of PP.     

Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H₂O and CO₂) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.