Flame Retardant Synergism of Hydroxy Silicone Oil and Al(OH)3 in EVA Composites

A synergistic effect on flame retardancy was found when hydroxy silicone oil (HSO) was incorporated into ethylene vinyl acetate/aluminum hydroxide (EVA/ATH) composite. The fire performance of EVA and EVA composites was studied by using limiting oxygen index (LOI), UL 94, and cone calorimeter test (CCT). Compared with the EVA/ATH binary composite, the LOI values of the EVA/ATH/HSO ternary composites at the same additive loading are all decreased. The CCT data indicated that the addition of HSO in EVA/ATH system not only reduces the heat release rate, but also prolonged the ignition time of the composite. Thermogravimetric analysis revealed that ATH accelerated the loss of acetic acid, but hydroxy silicone oil assisted to reduce ATH's accelerating effect.     

壳聚糖/聚磷酸铵膨胀阻燃PP的阻燃及抑烟性能

为了提高聚丙烯(PP)的阻燃和抑烟性能,将壳聚糖(CS)作为膨胀型阻燃剂的碳源、聚磷酸铵(APP)作为膨胀型阻燃剂的酸源和气源,在此基础上通过熔融共混的方法制备了PP/CS/APP复合材料。采用极限氧指数仪、锥形量热仪等仪器研究了PP/CS/APP复合材料的的抑烟性及阻燃性。研究结果表明:CS/APP添加量为30%时,复合材料的极限氧指数值最大可达28.1%;且复合材料在烟气释放总量、CO和CO_2排放上明显降低,抑烟性得到了提升;热释放速率峰值、平均热释放速率值、平均有效燃烧热值、总热释放量值降低,成炭率升高,PP/CS/APP复合材料更难点燃;火灾性能指数明显提高,阻燃性能得到了大幅度提升,火灾蔓延指数显著减小,同时火灾危险性也相应降低。     

Thermal degradation and combustion behavior of intumescent flame‐retardant polypropylene with novel phosphorus‐based flame retardants

The objective of this study was to develop an environmentally friendly fire‐retardant polypropylene (PP) with significantly improved fire‐retardancy performance with a novel flame‐retardant (FR) system. The system was composed of ammonium polyphosphate (APP), melamine (MEL), and novel phosphorus‐based FRs. Because of the synergistic FR effects among the three FRs, the FR PP composites achieved a V‐0 classification, and the limiting oxygen index reached as high as 36.5%. In the cone calorimeter test, both the peak heat‐release rate (pHRR) and total heat release (THR) of the FR PP composites were remarkably reduced by the incorporation of the novel FR system. The FR mechanism of the MEL–APP–FR–PP composites was investigated through thermogravimetric analysis and char residue characterization, and the results reveal that the addition of MEL–APP–FRs promoted the formation of stable intumescent char layers. This led to the reduction of pHRR and THR and resulted in the improvement of the fire retardancy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45962.     

Synergistic effects between red phosphorus and alumina trihydrate in flame retardant silicone rubber composites

Abstract

The synergistic flame retardant effects between red phosphorus (RP) and alumina trihydrate (ATH) in silicone rubber (SR) composites were evaluated using limiting oxygen index, UL 94 rating, cone calorimeter, thermogravimetric analysis and digital photographs. It has been found that the SR composite containing only ATH does not show good flame retardancy at 39·0 wt-% loading. The cone calorimeter results showed that the heat release rate, mass loss rate, mass and total heat release of SR/ATH/RP composites decrease greatly in comparison with the SR/ATH composites. The digital photographs demonstrated that 1·0 wt-%RP could promote the formation of the homogenous and compact char layer. Thus, a suitable amount of RP has a synergistic effect with ATH in the flame retardant SR composite system.     

有机-金属杂化化合物阻燃聚丙烯的研究

将有机-金属杂化三嗪化合物（SCTCFA-ZnO）与聚磷酸铵（APP）复配制备了膨胀型阻燃剂（IFR）,通过极限氧指数测试、垂直燃烧测试、锥形量热分析、热失重分析和扫描电子显微镜分析等表征方法研究了SCTCFA-ZnO/APP的协同作用对PP复合材料阻燃性能的影响。结果表明,APP与SCTCFA-ZnO复配可以有提高PP材料的阻燃性能,当IFR的添加量为25 %（质量分数,下同）,且APP/SCTCFA-ZnO的质量比为2/1时,复合材料的极限氧指数最高,达到31.1 %,达到UL 94 V-0级;IFR可提高复合体系的温热稳定性,阻燃复合材料燃烧后会形成一层致密、连续的炭层,从而起到良好的阻燃效果。     

氧化锌对膨胀阻燃聚丙烯的影响

研究了协效剂氧化锌（ZnO）对聚磷酸铵（APP）、季戊四醇（PER）、氰尿酸三聚氰胺（MCA）膨胀阻燃聚丙烯（PP）体系的阻燃协效作用。采用氧指数（LOI）、热失重法（TG）、锥形量热仪（Cone）、红外光谱（FTIR）等手段分析了ZnO对膨胀阻燃PP的影响。结果表明，氧化锌可提高该体系的LOI和阻燃性能，还可促进阻燃体系形成炭层，且可提高其炭层的强度，该体系氧化锌最佳用量应为1．0份。     

MPP/PER/APP阻燃PP的阻燃及热裂解行为

采用聚磷酸蜜胺(MPP)／季戊四醇(PER)／聚磷酸铵(APP)三元膨胀型阻燃剂(IFR)阻燃聚丙烯(PP),测定了阻燃PP的极限氧指数(LOI)、UL94V阻燃性及热稳定性,以傅里叶变换红外光谱(FTIR)分析了阻燃PP的热分解残余物。以锥形量热仪(CONE)测定了阻燃PP的诸多与火灾有关的阻燃参数,包括释热速度、质量损失速度、总释热量、有效燃烧热、比消光面积及引燃时间等,以光电子能谱(XPS)测定了阻燃PP残炭表面的元素组成及XPS曲线拟合数据,还以扫描电镜(SEM)观测了阻燃PP残炭的形态。     

Study on surface modification and flame retardants properties of ammonium polyphosphate for polypropylene

Microencapsulation ammonium polyphosphate used as flame‐retardant in polypropylene was prepared with hydroxyl silicone oil (HSO) and melamine‐formaldehyde (MF) resin in this article. Fourier transform infrared and energy dispersive spectrometer were used to identify the structure of HSO‐MFAPP. For the HSO‐MFAPP/polypropylene (PP) composites, the flame retardant effect was evaluated by the limiting oxygen index and UL‐94 testing, the compatibility was observed with scanning electron microscope, and the thermal stability was studied by thermogravimetric analysis. The results showed that the microencapsulation of ammonium polyphosphate (APP) with HSO‐MF was prepared by in situ polymerization, and the flame retardant properties and water resistance of the PP/HSO‐MFAPP/pentaerythritol (PER) composites were much better than the ones of the PP/APP/PER composites. Moreover, the compatibility of HSO‐MFAPP with PP was better than that of unmodified APP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Flame retardancy and mechanical properties of thermal plastic composite panels made from Tetra Pak waste and high‐density polyethylene

In this article, flame retardancy thermoplastic composites were developed by extrusion followed by injection molding using recycled Tetra Pak packaging material (TPP) waste and high‐density polyethylene (HDPE) with addition of ammonium polyphosphate (APP) and melamine (MEL) as intumescent flame retardants (FRs). The influences of intumescent FRs on the properties of composites were investigated. FRs loading positively affected flame retardancy, but deteriorated mechanical properties as the loading rate was more than 30 wt%. Considering the fire retardancy and tensile strength (TS), the content of FR should not be more than 30 wt%. When the ratio of APP/MEL was less than 3/1, both combustion behavior and TS of the composites were improved with the increased FR loading, which was supported and verified by the analysis of FTIR spectra and SEM images. The thermogravimetric analysis results indicated that the incorporation APP and/or APP and MEL into composites as FRs into composites promoted char formation and correspondingly improved the thermal stability. The synergistic effect of APP and MEL in the intumescent FR system further improved the flame retardancy of the composites. POLYM. COMPOS., 37:1797–1804, 2016. © 2014 Society of Plastics Engineers     

Effect of Phosphorus-Based Flame Retardants and PA6 on the Flame Retardancy and Thermal Degradation of Polypropylene

The investigation mainly focuses on the effect of polyamide 6 (PA6) and phosphorus based flame retardants (FRs) on improving the flame retardancy of polypropylene (PP). The flame retardant properties have been studied by limiting oxygen index, vertical burning test tests and cone calorimeter testing. The results demonstrate that PA6 and FRs can greatly improve the flame-retardant and thermal properties of PP. It’s found that the addition of PA6/APP/FRs can promote the formation of stable intumescent char layers. Those indicate that the flame retardancy of PA6/APP/FRs/PP composites is improved by the condensed-phase action of PA6/APP/FRs.     

聚苯乙烯的无卤阻燃研究

采用正交设计法分析了聚磷酸胺(APP)、季戊四醇(PER)、三聚氰胺(MEL)作为一种混合体系对聚苯乙烯(PS)的阻燃作用。实验表明,酸源、炭源、气源组成的膨胀型阻燃剂有良好的阻燃效果,PER对PS阻燃性能的影响显著。各个因子对材料力学性能和加工性能的影响不同:PER用量是影响拉伸强度、弯曲强度和流动性的主要因素;APP用量是影响无缺口冲击强度的主要因素;MEL用量是影响缺口冲击强度的主要因素。当APP、PER、MEL 的用量分别为30,20,5摩尔份时,阻燃PS获得较好的综合性能。     

Flame Retardancy and Thermal Performance of Polypropylene Treated With the Intumescent Flame Retardant,Piperazine Spirocyclic Phosphoramidate

Piperazine spirocyclic phosphoramidate (PSP), a novel halogen‐free intumescent flame retardant, was synthesized and used to improve the flame retardancy and dripping resistance of polypropylene (PP) combined with ammonium polyphosphate (APP) and a triazine polymer charring‐foaming agent (CFA). The optimum flame‐retardant formulation was PSP:APP:CFA = 3:6:2 (weight ratio). The flammability and thermal behavior of the (intumescent flame‐retardant)‐PP (IFR‐PP) were investigated via limiting oxygen index (LOI), vertical burning tests (UL‐94), thermogravimetric analysis, and cone calorimetry (CONE). The results indicated that the IFR‐PP had both excellent flame retardancy and anti‐dripping ability. The optimum flame‐retardant formulation gave an LOI value of 39.8 and a UL‐94 V‐0 rating to PP. Moreover, both the heat release rate and the total heat release of the IFR‐PP with the optimum formulation decreased significantly relative to those of pure PP, according to the cone calorimeter analyses. The residues of IFR‐PP obtained after CONE tests were observed by scanning electron microscopy, and it was found that the char yield was directly related to the flame retardancy and anti‐dripping behavior of the treated PP. J. VINYL ADDIT. TECHNOL., 20:10–15, 2014. © 2014 Society of Plastics Engineers     

Synergistic effect between silicone‐containing macromolecular charring agent and ammonium polyphosphate in flame retardant polypropylene

A novel silicone‐containing macromolecular charring agent (Si‐MCA) was synthesized via polycondensation, and it was combined with ammonium polyphosphate (APP) to flame retard polypropylene (PP). The results showed that Si‐MCA exhibited a good synergistic effect with APP in flame retardant PP. When the content of APP was 18.7 wt % and Si‐MCA was 6.3 wt %, the limiting oxygen index value of the PP/APP/Si‐MCA composite was 33.5%, and the vertical burning (UL 94) test classed a V‐0 rating. The peak heat release rate, total heat release, average mass loss rate, and total smoke production of the composite were also decreased significantly. Moreover, the PP/APP/Si‐MCA composite showed an outstanding water resistance. After soaking in 70°C water for 168 h, the PP/APP/Si‐MCA composite could still reach a UL 94 V‐0 rating at 20.0 wt % IFR loading, whereas the PP/APP/PER composite failed to pass the UL 94 test even at 25.0 wt % IFR loading. Thermogravimetric analysis, thermogravimetry‐Fourier transform infrared spectrometry, and scanning electron microscopy‐energy dispersive X‐ray spectrometry results revealed that a compact and thermostable intumescent char was formed by APP/Si‐MCA during burning, thus effectively improved the flame retardancy of PP. The possible synergistic mechanism between APP and Si‐MCA was also discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41580.     

Effect of charring agent THEIC on flame retardant properties of polypropylene

Tris(2‐hydroxyethyl) isocyanurate (THEIC) was used as charring agent and combined with ammonium polyphosphate (APP) to form an intumescent flame retardant (IFR) for polypropylene (PP). The flame retardancy and combustion performance of PP/IFR composite was tested by limiting oxygen index (LOI), UL‐94 vertical burning test and cone calorimeter. The results showed that PP/IFR composite had highest LOI of 34.8 and obtained V‐0 rating when 30 wt % IFR was loaded and mass ratio APP/THEIC was 2 : 1. The peak heat release (PHRR) and total heat release (THR) values of PP composite containing FRs were remarkably reduced compared with that of pure PP. However, water resistant test demonstrated the PP/IFR composite had poor flame retardant durability, both the LOI value and UL‐94 V‐rating decreased when PP/IFR composite was soaked in water at 70°C after 36 h. The degradation process and the char morphology of IFR and PP/IFR composite were investigated by TGA and SEM images. The possible reaction path between APP and THEIC in the swollen process was proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41214.     

Component ratio effects of hyperbranched triazine compound and ammonium polyphosphate in flame‐retardant polypropylene composites

A hyperbranched derivative of triazine group (EA) was synthesized by elimination reaction between ethylenediamine and cyanuric chloride. The different‐mass‐ratio EA and ammonium polyphosphate (APP) were mixed and blended with polypropylene (PP) in a constant amount (25%) to prepare a series of EA/APP/PP composites. The component ratio effect of EA/APP on the flame‐retardant property of the EA/APP/PP composites was investigated using the limiting oxygen index (LOI), vertical burning (UL‐94), and cone calorimetry tests. Results indicated that the EA/APP/PP (7.50/17.50/75.00) composite with the appropriate EA/APP mass ratio had the highest LOI, UL94 V‐0 rating, lowest heat release rate, and highest residue yield. These results implied that the appropriate EA/APP mass ratio formed a better intumescent flame‐retardant system and adequately exerted their synergistic effects. Furthermore, average effective combustion heat values revealed that EA/APP flame retardant possessed the gaseous‐phase flame‐retardant effect on PP. Residues of the EA/APP/PP composites were also investigated by scanning electron microscopy, Fourier‐transform infrared, and X‐ray photoelectron spectroscopy. Results demonstrated that the appropriate EA/APP mass ratio can fully interact and lock more chemical constituents containing carbon and nitrogen in the residue, thereby resulting in the formation of a dense, compact, and intumescent char layer. This char layer exerted a condensed‐phase flame‐retardant effect on EA/APP/PP composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41006.     

Microencapsulated ammonium polyphosphate by polyurethane with segment of dipentaerythritol and its application in flame retardant polypropylene

Dipentaerythritol (DPER), 4, 40-diphenylmethanediisocyanate (MDI) and melamine (MEL) are used as raw materials to microencapsulate ammonium polyphosphate (MAPP) in situ polymerization. The MAPP is characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The results show that the coating operation can effectively improve water resistance of ammonium polyphosphate (APP), and MAPP has higher residual rate than that of APP after combustion. The flame retardant action of MAPP and APP in polypropylene (PP) is investigated by the limited oxygen index (LOI), vertical burning test (UL-94), TGA, SEM, and cone calorimeter test (CCT). The LOI value of the PP/MAPP composite at the same loading is higher than that of PP/APP composite. UL 94 ratings of PP/MAPP composites are raised to V-0 at 20 wt% loading. The results of CCT also show that MAPP is more efficient than APP. The morphological structures observed by digital photos and SEM demonstrated that MAPP could be promoted to form the continuous and compact intumescent char layer. The flame retardant mechanism of PP/MAPP is also discussed.     

Flammability and thermal degradation of intumescent flame‐retardant polypropylene composites

The flammability of polypropylene (PP) composites containing intumescent flame‐retardant additives, i.e., melamine pyrophosphate (MPP) and 1‐oxo‐4‐hydroxymethyl‐2,6,7‐trioxa‐1‐phosphabicyclo[2.2.2]octane (PEPA) was characterized by limiting oxygen index (LOI), UL 94 test, and cone calorimeter. In addition, the thermal degradation of the composites was studied using thermogravimetric analysis (TG) and real‐time Fourier transform infrared (RTFTIR). It has been found that the PP composite only containing MPP (or PEPA) does not show good flame retardancy even at 30% additive level. Compared with the PP/MPP binary composite, the LOI values of the PP/MPP/PEPA ternary composites at the same additive loading are all increased, and UL 94 rating of the ternary composite (PP3) studied is raised to V‐0 rating from no rating (PP/MPP). The cone calorimeter results show that the heat release rate of some ternary composites decreases in comparison with the binary composite. It is noted from the TG data that initial decomposition temperatures of ternary composites are lower than that of the binary composites. The RTFTIR study indicates that the PP/MPP/PEPA composites have higher thermal oxidative stability than the pure PP. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

PP/纳米蒙脱土复合材料炭层结构对阻燃性能的影响

采用熔融插层法制备了不同纳米蒙脱土含量的聚丙烯(PP)/有机蒙脱土(OMMT)和PP/无机蒙脱土(MMT)复合材料,且评价了复合材料的阻燃性能:采用数码相机、扫描电子显微镜观察了燃烧残余物结构.加入OMMT可显著提高PP/OM MT的阻燃性能:纯PP的热释放速率(HRR)峰值为1 337.59 kW/m2;w(OMMT...     

膨胀阻燃三元乙丙橡胶/聚丙烯热塑性硫化胶的性能

分析了膨胀型阻燃剂聚磷酸铵(APP)、季戊四醇(PER)的加入方式对三元乙丙橡胶(EPDM)/聚丙烯(PP)体系硫化特性的影响,研究了加入不同膨胀型阻燃剂及协效剂硼酸锌(ZB)、有机蒙脱土(OMMT)对动态硫化EPDM/PP热塑性硫化胶(EPDM/PPTPV)性能的影响。结果表明,在动态硫化前加入APP或PER时,EPDM/PP体系不能进行硫化;当APP的加入量为30份时,EPDM/PPTPV的综合力学性能较佳;在EPDM/PPTPV中同时加入APP、PER、三聚氰胺(MEL)时,随着三者加入量的增加,体系的阻燃性能增强,但拉伸强度明显降低,三者的最佳用量为30份APP、10份PER、10份MEL,此时体系的黏度与纯EPDM/PPTPV相当;加入ZB或OMMT时,EPDM/PPTPV的拉伸强度降低,且加入OMMT体系的阻燃效果优于加入ZB体系;加入OMMT时,在低剪切速率下,体系的黏度减小;在高剪切速率下,体系的黏度增大;加入ZB时,在低剪切速率下,体系的黏度与未加ZB体系相当;在高剪切速率下,体系的黏度增大。     

Catalytically synergistic effects of novel LaMnO3 composite metal oxide in intumescent flame‐retardant polypropylene system

The newly prepared LaMnO₃ was introduced as a novel perovskite composite metal oxide catalyst for the first time to improve the flame retardancy of flame‐retarded (FR) polypropylene with intumescent flame‐retardant (IFR) system consisting of ammonium polyphosphate (APP), pentaerythritol (PER), and melamine (MA). The synergistic effects of LaMnO₃ catalyst on the performance of IFR PP composites as well as the corresponding catalytically synergistic FR mechanism were investigated. The experimental results show that the incorporated LaMnO₃ catalyst plays an excellently catalytic and synergistic part in improvement of the flame retardancy of FR PP system. Compared with FR system without LaMnO₃, the incorporation of only 0.5 wt% LaMnO₃ into PP FR system could obviously improve the UL‐94 level from failure to V‐0 rating and decrease the micro‐scale calorimetry parameters peak heat release rate and heat release capacity. The remarkable improvement in flammability can be ascribed to the catalytic carbonization effect of LaMnO₃ on the intumescent flame retardant PP system. The incorporation of appropriate amount of LaMnO₃, on one hand, could improve the thermal stability of FR PP material, and on the other hand, could also act as nuclei to induce formation of the continuous, compact and smooth condensed phase intumescent charred layer with radialized spherulite‐like structure. As a result, the char yield and also the quality of the formed condensed phase charred layers are correspondingly enhanced remarkably, which is beneficial to improvement of the FR properties. POLYM. COMPOS., 35:2390–2400, 2014. © 2014 Society of Plastics Engineers