三聚氰胺聚磷酸盐/硼酚醛协效体系阻燃PA66/GF复合材料的研究

采用氮磷型阻燃剂三聚氰胺聚磷酸盐(MPP)与硼改性酚醛树脂(BPF)组成的复合阻燃体系对玻纤(GF)增强尼龙66( PA66)复合材料进行阻燃,获得了阻燃性能优异、力学性能良好的增强复合材料,研究了协效阻燃剂BPF/MPP配比、BPF/MPP用量及GF用量对阻燃复合材料阻燃性能的影响,采用微型燃烧量热和质量保持率分析方法研究了阻燃复合材料的燃烧及成炭行为,对复合阻燃剂的协效机理进行了讨论.结果表明,当BPF在BPF/MPP中的质量分数为15％时,添加25％ BPF/MPP复合阻燃剂可使20％ GF增强PA66复合材料达到V-0( 1.6 mm)阻燃级别,极限氧指数增加至25.3％,拉伸强度、弯曲强度、缺口冲击强度分别为116 MPa,132 MPa,7.1 kJ/m2.该复合材料可满足高性能无卤阻燃的使用要求.     

硼酸锌对氮磷协效阻燃玻纤增强尼龙66性能的影响

为提高三聚氰胺聚磷酸盐(MPP)和二乙基次膦酸盐(OP)协效阻燃玻纤(GF)增强尼龙66(PA66)的综合性能,引入少量的无机阻燃剂硼酸锌(ZB)作为协效剂,系统研究了不同添加量的ZB对阻燃材料的阻燃性能、热稳定性、力学性能和白度的影响。结果表明,当MPP和OP的总添加量为15%,复配0.5%的ZB时,阻燃GF增强PA66的垂直燃烧阻燃等级达到UL94 V–0级,且热释放总量由MPP/OP体系的15.4 k J/g降为13.7 k J/g;ZB的引入促进了连续、致密炭层的形成,增强了凝聚相阻燃;ZB增强了阻燃材料的热稳定性,ZB复配量为1.0%的阻燃材料的初始降解温度提高到了301℃,有效避免了加工过程中的降解;当ZB添加量为1.0%时,阻燃材料的拉伸强度和缺口冲击强度分别为100.9 MPa和4.22 k J/m~2,均优于未添加阻燃剂的纯GF增强PA66;同时,样品的白度得到了明显提升,有利于阻燃GF增强PA66的工业化应用。     

The investigation of intumescent flame‐retardant polypropylene using a new macromolecular charring agent polyamide 11

This article deals with a new macromolecular charring agent, polyamide 11 (PA11), which is in combination with a small charring agent, pentaerythritol (PER) and a flame retardant, ammonium polyethylene to flame‐retardant polypropylene (PP). When compared with polyamide 6 (PA6), an existing macromolecular charring agent extensively reported, PA11 has longer alkyl segment in its chain unit and shows better compatibility with PP; additionally, with a relatively lower melt point close to that of PP, PA11 can be more effectively compounded with PP in the melt state and better dispersed in PP matrix, thus enhancing the flame retardancy and mechanical properties. Moreover, with certain synergistic effects between PA11 and PER, the system using PA11/PER as composite charring agents showed better charring performance in comparison with the system only using PER. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

聚磷酸三聚氰胺对玻纤增强PA66的膨胀阻燃作用

采用自制的新型膨胀型阻燃剂——聚磷酸三聚氰胺(MPP)对玻纤增强PA66进行阻燃,以氧指数和垂直燃烧(UL94)评价了其阻燃作用;以热失重测定了材料的热分解性能;以扫描电镜观察了材料残炭的结构;并探讨了MPP阻燃玻纤增强PA66的阻燃机理。试验表明,单一MPP对玻纤增强PA66有良好的阻燃效果,当添加25％时,阻燃材料的氧指数为38,0％,达到UL94V-0级;MPP参与了玻纤增强PA66的降解过程,在材料表面形成了致密的隔热、隔氧的泡沫炭层。     

三聚氰胺氰尿酸盐/聚氨酯复合阻燃剂阻燃PA66的研究

采用三聚氰胺氰尿酸盐(MCA)/聚氨酯(TPU)复合阻燃剂阻燃PA66,解决了单独使用MCA阻燃PA66熔滴引燃脱脂棉问题,可使1．6 mm样条通过UL94V-0级别；研究了MCA/TPU复合阻燃剂阻燃PA66的阻燃机理,考察了阻燃材料的力学性能。     

Synergistic flame‐retardant effect of phosphaphenanthrene derivative and aluminum diethylphosphinate in glass fiber reinforced polyamide 66

The synergistic flame‐retardant (FR) effect of 1,1′‐bis(4‐hydroxyphenyl)‐metheylene‐bis(9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide‐2‐hydroxypropan‐1‐yl) (DPOH) and aluminum diethylphosphinate (AlPi) composites on glass fiber reinforced polyamide 66 (PA) was investigated by limiting oxygen index (LOI) tests, vertical burning (UL94) tests, and cone calorimeter tests. DPOH/AlPi system with 1:1 mass ratio increased UL94 ratings, suppressed heat release rate and increased residue yields of PA composites, and DPOH/AlPi system also imposed high LOI values and lower total heat release values to PA composites. All these results verified excellent synergistic FR effect between DPOH and AlPi. The reason of DPOH/AlPi system with higher flame‐retardant efficiency was caused by the quenching effect as good as that of DPOH and also by the higher charring effect than that of AlPi. DPOH/AlPi system possesses good flame retardancy in gas phase and also the strengthened FR effect in condensed phase compared with DPOH and AlPi alone, which led to excellent synergistic FR effect between the two components DPOH and AlPi. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45126.     

The investigation of melamine polyphosphate flame retardant polyamide‐6/inorganic siliciferous filler with different geometrical form

Melamine polyphosphate (MpolyP) was used to flame retard polyamide‐6 filled with siliciferous fillers including fibrous wollastonite, laminar talc, and spherical glass bead. The mechanical performance, flame retardancy of these flame retarded materials, and the influence of these fillers on charring behavior were investigated. The results show that wollastonite/MpolyP/PA6 system has the best mechanical properties as compared with talc/MpolyP/PA6 and glass bead/MpolyP/PA6 system due to good reinforcing effects of the fibrous filler in resin matrix. Otherwise, the char morphology observation shows that spherical glass beads separates from the char matrix during the expansion of the char layer, which hardly improves the char quality. However, fibrous wollastonite and laminar talc can well combine with the char layer, thus enhancing the flame retardancy as a part of the charred layer. It is proved that the laminar talc favors the formation of more condensed char because of its barrier effects, and the fibrous wollastonite with quite high aspect ratio can effectively reinforce both the resin and the charred layer, which leads to the remarkable improvement of the flame retardancy. Consequently, polyamide‐6/MpolyP/wollastonite system shows the best flame retardancy among the above systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Using PA6 as a charring agent in intumescent polypropylene formulations based on carboxylated polypropylene compatibilizer and nano‐montmorillonite synergistic agent

The intumescent fire retardant polypropylene (IFP/PP) filled with ammonium polyphosphate (APP), melamine (M), and PA6 (charring agent) is discussed. Intumescing degree (ID) and the char yield were determined. Only when the three main components of IFR coexist at appropriate proportions, it has optimal ID and higher char yield. The appropriate proportion is PA6 : APP : M = 10 : 10 : 5. A new compatibilizer, carboxylated polypropylene (EPP), was added to PP/PA‐6 blend. Flow tests indicated that the apparent viscosity increased with the addition of EPP, thermal characterization suggested that EPP has reacted with PA6, PA6‐g‐EPP cocrystallized with PA6, and EPP‐g‐PA6 cocrystallized with PP; SEM micrographs illustrated that the presence of EPP improved the compatibility of PP and PA6. All the investigations showed that EPP was an excellent compatibilizer, and it was a true coupling agent for PP/PA6 blends. Using PA6 as a charring agent resulted in the IFR/PP dripping, which deteriorated the flammability properties. The addition of nano‐montmorillonite (nano‐MMT) as a synergistic agent of IFR enabled to overcome the shortcoming. The tensile test testified that the addition of nano‐MMT enhanced the mechanical strength by 44.3%. SEM showed that nano‐MMT improved the compatibility of the composites. It was concluded that the intumescent system with nano‐MMT was an effective flame retardant in improving combustion properties of polypropylene. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 739–746, 2006     

Melamine polyphosphate/silicon‐modified phenolic resin flame retardant glass fiber reinforced polyamide‐6

The halogen‐free flame retardance of glass fiber reinforced polyamide‐6 (PA6) is an everlastingly challenge due to well‐known wick effect. In this research, a novel system composed of a nitrogen–phosphorous flame retardant, melamine polyphosphate combined with a macromolecular charring agent, silicon‐modified phenolic resin (SPR), was employed to flame‐retard glass fiber reinforced PA6. It exhibited obvious synergistic effect between the two components at a proper ratio range. The flame retardance of the composites can be remarkably improved due to the increased amount and improved thermal stability of the produced char. The flame resistance tests indicated that the synergism system with an optimized ratio achieved V0 (1.6 mm) rating of UL94, 25.2% of Limited Oxygen Index, and only 338.2 W/g of the heat release peak rate. The corresponding synergistic mechanisms were investigated by the characterizations including the thermal gravimetric analysis, carbonation test, and the char morphology observation. It confirmed that the introduced SPR could accelerate the carbonation of PA6 resin, which was in favor of the construction of denser and more continuous charring structure. In addition, the flame retardant materials also indicated the acceptable mechanical properties, showing the advantages in the overall performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of novel copolyamide charring agents on flame‐retarded polypropylene

In this article, two novel copolyamide charring agents, ES‐6 and M‐170, were served as charring agents or synergist with ammonium polyphosphate (APP) and dipentaerythritol (DPER) for the flame‐retarded polypropylene (PP). The flame‐retardant system was characterized by limiting oxygen index (LOI), tensile strength, Izod impact strength, thermogravimetric analyses, differential scanning calorimeter (DSC), and scanning electron microscope (SEM). Compared with polyamide 6 (PA6), ES‐6 and M‐170 had better dispersion and compatibility in the PP matrix and enhanced mechanical properties. Meanwhile, as low melting point polyamides, ES‐6 and M‐170 could decrease processing temperature and effectively inhibit side reaction, especially the degradation of APP. In addition, the synergistic effect between ES‐6 and DPER was also investigated. The results showed that the synergistic system containing ES‐6 had better flame retardancy and mechanical performance in comparison with the system only using DPER or the system containing PA6. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

Influence of polyamide 6 as a charring agent on the flame retardancy,thermal, and mechanical properties of polypropylene composites

In this work, polyamide 6 (PA6) as a charring agent has been used in combination with thermoplastic polyurethane (TPU)‐microencapsulated ammonium polyphosphate (MTAPP) forming intumescent flame retardants (IFRs) which applies in polypropylene (PP). The effects of the IFRs on the flame retardancy, morphology of char layers, water resistance, thermal properties and mechanical properties of flame‐retardant PP composites are investigated by limiting oxygen index (LOI), UL‐94 test, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical properties test. The results show that the PP/MTAPP/PA6 composites exhibit much better flame‐retardant performances than the PP/MTAPP composites. The higher LOI values and UL‐94 V‐2 of the PP/MTAPP composites with suitable amount of PA6 are obtained, which is attributed to the thick and compact char layer structure evidenced by SEM. The results from TGA and DSC demonstrate that the introduction of PA6 into PP/MTAPP composites has a great effect on the thermal stability and crystallization behaviors of the composites. Furthermore, the mechanical properties of PP/MTAPP/PA6 composites are also improved greatly due to the presence of PA6 as a charring agent. POLYM. ENG. SCI., 55:1355–1360, 2015. © 2015 Society of Plastics Engineers     

Synthesis of in situ encapsulated intumescent flame retardant and the flame retardancy in polypropylene

In this article, a nitrogen–phosphorus composite flame retardant, melamine phosphate (MP), was synthesized in a solution of phosphoric acid/macromolecular charring agent, polyamide 6 (PA6). With the progress of the phosphoric acid–melamine reaction producing MP, the acidity of this system decreased and the originally dissolved PA6 resin precipitated on the surface of MP particles to obtain the MP in situ encapsulated by PA6. This encapsulated MP was incorporated with a small molecular charring agent, pentaerythritol (PER), composed of an intumescent system to flame retard polypropylene (PP). As a result of the isolation effects of PA6 resin, the esterfication reaction between MP and PER was effectively suppressed at the processing temperature of PP, thus remarkably improving the thermal stability of such an intumescent system while maintaining the mechanical performance of the flame retardant PP. Additionally, encapsulated MP/PER system showed better charring properties when compared with MP/PER and therefore possessed a higher efficiency in flame retarding PP. The corresponding charring mechanisms of the former, including either a macromolecular charring agent or small molecular one, were investigated. POLYM. COMPOS., 28:163–167, 2007. © 2007 Society of Plastics Engineers     

Synergistic effect between a triazine‐based macromolecule and melamine pyrophosphate in flame retardant polypropylene

A novel charring agent, namely triazine‐based macromolecule (TBM), was synthesized via solution polycondensation of cyanuric chloride, ethanolamine, and diethylenetriamine. The prepared charring agent possessed little water solubility and superior char‐forming ability, and it showed good synergistic effects with melamine pyrophosphate (MPP) in flame retardant polypropylene (PP). When the content of MPP was 16.7 wt% and TBM was 8.3 wt%, the limiting oxygen index (LOI) of the PP/MPP/TBM composite could reach 31.0%, and a UL‐94 V‐0 rating was achieved based on the vertical burning test. Furthermore, the composite exhibited an outstanding water resistance that it could still obtain a V‐0 rating after soaking in hot water for 168 h. The cone calorimetry test (CCT) results demonstrated that the peak heat release rate (PHRR), the total heat release (THR) and mass lose rate (MLR) of the composite were decreased significantly in comparison with those of pure PP. The thermogravimetric analysis (TGA), thermogravimetry‐Fourier transform infrared spectrometry (TG‐FTIR), and scanning electron microscopy‐energy dispersive spectra (SEM‐EDS) results revealed that the efficient flame retardancy of MPP/TBM was mainly attributed to the formation of a compact and thermostable intumescent char on underlying materials during a fire. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

Flame retardancy and mechanical properties of polyamide 6 with melamine polyphosphate and ionic liquid surfactant‐treated montmorillonite

The mechanical properties and inflammability of polyamide 6 (PA6) nanocomposites incorporated with Montmorillonite organoclay (MMT) modified with thermal stable ionic liquid surfactants were investigated. The compatibility between ionic liquid‐treated MMT and PA6 matrix was improved and the intercalation morphology was achieved, which resulted in the increaseof tensile modulus. However, the addition of organo‐MMTs alone did not improve the inflammability of the PA6 nanocomposite, because of strong melt‐dripping behavior of PA6 matrix. Addition of auxiliary melamine polyphosphate (MPP) intumescent flame retardant to the nanocomposite prevented the melt dripping and enhanced inflammability performance. The enhanced inflammability of PA6/organoclay/MPP nanocomposites was attributed to the synergistic effect between imidazolium or phosphonium organo‐MMTs and intumescent flame retardant MPP. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40648.     

Thermal stability,flame retardance,and mechanical properties of polyamide 66 modified by a nitrogen–phosphorous reacting flame retardant

Flame‐retardant polyamide 66 (PA66) was prepared by the polymerization between PA66 prepolymer and N‐benzoic acid (ethyl‐N‐benzoic acid formamide) phosphamide (NENP). Compared with the pure PA66, the flame‐retardant PA66 exhibited better thermal stability, as indicated by thermogravimetric analysis results. The limiting oxygen index was 28% and the UL‐94 test results of the flame‐retardant PA66 indicated a V‐0 rating when the content of the NENP prepolymer was 5 wt %. The flammability and flame‐retardant mechanism of PA66 were also studied with cone calorimetry and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, respectively. The mechanical properties results show that the flame‐retardant PA66 resin had favorable mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43538.     

Melamine cyanurate surface treated by nylon of low molecular weight to prepare flame‐retardant polyamide 66 with high flowability

In the present research, a nitrogen‐based flame‐retardant, melamine cyanurate (MCA) was surface‐treated with low‐molecular‐weight nylon through a solvent process to further improve its flowability and dispersion. The surface energy and flow energy of the modified MCA were investigated. The properties of polyamide 66 (PA66) prepared with surface‐treated and with conventional MCA were evaluated and compared. Because of lower surface energy and flow energy for modified MCA, its agglomeration degree and flow resistance are obviously decreased compared with conventional MCA, thus achieving finer and more homogenous dispersion in the PA66 matrix. Moreover, the low‐molecular‐weight nylon resin encapsulating MCA surface will melt at lower temperature during compounding with PA66; hence, it serves as a lubricant and carrier to further improve the flowability and dispersion of the flame retardants. Based on these advantages, the modified MCA flame‐retardant PA66 achieves much better flame retardancy, flowability, and mechanical properties compared with conventional MCA/PA66 under the same loading level of flame retardant (10 wt%).     

磷氮阻燃剂/协效剂对PA9T的阻燃性、热稳定性的影响

探究二乙基次磷酸铝(ADP)、三聚氰胺聚磷酸盐(MPP)及不同协效剂(勃姆石、无水硼酸锌(ZnB)、锡酸锌、三氧化钼)对PA9T阻燃性能的影响,且定量分析阻燃体系的分散性,同时分析阻燃体系的阻燃机理。结果表明:当m(ADP)∶m(MPP)=2∶1,PA9T/ADP/MPP的LOI值为38.5%,UL-94达到V-0级,阻燃效果最佳。PA9T/13.3%ADP/6.7%MPP的实际残炭率高于理论残炭率,表明ADP/MPP的引入促使PA9T在凝聚相交联成炭。协效剂对PA9T阻燃性能的影响程度排序为:ZnB>三氧化钼>锡酸锌>勃姆石。PA9T/FR/ZnB复合材料的烟气释放最低,燃烧后碳氢化合物的释放量显著降低,CO₂释放量提高。复合材料燃烧后形成连续、致密的炭层,且炭层中存在磷酸类物质、碳氧化物及铝氧化物等,具有典型的凝聚相阻燃机理。     

Flame retarding glass fibers reinforced polyamide 6 by melamine polyphosphate/polyurethane‐encapsulated solid acid

Melamine polyphosphate and thermal‐plastic polyurethane (TPU)‐encapsulated solid acid were applied for flame retardant glass fibers reinforced polyamide 6 (GFPA6). The introduction of TPU would change the interfacial property between glass fibers (GFs) and polyamide 6 (PA6), weakening the “candlewick effects” of GFs in PA6. Serving as a synergist, solid acid containing sulfur (CAS) played the role of a strong acid source, which could promote the system to form much more condensed and closed char layers. Macromolecular charring agent, TPU, was able to accelerate the charring process. In addition, TPU encapsulating on the unstable solid acid could isolate CAS from PA6 resin, preventing the chemical interaction between them, which would cause the degradation of material. This established technology provided an effective approach to prepare halogen‐free flame retardant GFPA6 with UL94‐1.6 mm V0 rating and good mechanical performance, showing a promise in the future commercial application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

添加PA66－MPP提高PP／GF增强塑料力学性能的研究

本文研究ＰＰ／ＧＦ（玻纤增强聚丙烯）的加工过程中，添加ＰＡ６６（尼龙）、ＭＰＰ（ＰＰ－ｇ－ＭＡＨ）进一步促进ＧＦ对ＰＰ的增强作用。考察了ＭＰＰ对ＰＰ／ＰＡ６６共混物的增容作用，ＰＡ６６、ＭＰＰ的组成配比对ＰＰ／ＧＦ增强塑料力学性能和微观结构的影响。结果表明：ＰＡ６６、ＭＰＰ的组成比对ＰＰ／ＧＦ的力学性能影响较大；较佳配比的ＰＡ６６、ＭＰＰ，可大幅度地提高增强塑料的力学性能。     

Intumescent flame retardation of melamine‐modified montmorillonite on polyamide 6: Enhancement of condense phase and flame retardance

Melamine‐modified montmorillonite (MA‐MMT) was prepared via cation exchange. The intercalation behavior was investigated by Fourier transform infrared spectrometer (FT‐IR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). The results showed that the d‐spacing value increased from 1.25 nm for Na‐montmorillonite (Na⁺MMT) to 1.53 nm for MA‐MMT. Different kinds of montmorillonite combined with melamine pyrophosphate (MPP) were used to prepare flame‐retardant polyamide 6 (FR‐PA6). Flame retardance of FR‐PA6 samples was investigated by limiting oxygen index (LOI), UL‐94 vertical burning method, and cone calorimeter test. Morphology and component of char residues for FR‐PA6 were investigated by scanning electron microscope (SEM) and XPS. It was found that MA‐MMT/MPP system contributed both excellent flame retardance and anti‐dripping ability for PA6. MA‐MMT particles can fill flaws of char residues and strengthen the char layer, leading to form more intumescent char layer. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers