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。     

无卤膨胀阻燃剂在低密度聚乙烯中的应用研究

以干法合成的P-N无卤膨胀阻燃剂(IFR)为基础,配合聚磷酸胺(APP)并且将金属氧化物(ZnO)作为协效剂阻燃改性低密度聚乙烯(PE-LD)。采用扫描电子显微镜对该体系燃烧后的炭层结构进行了分析。通过红外光谱和X射线光电子能谱研究了该体系在不同温度热处理后的残炭组成,并分析了该膨胀型阻燃体系对PE-LD的阻燃机理。结果表明,PE-LD/IFR/APP/ZnO体系的极限氧指数可以达到27.9%,垂直燃烧性能达到UL 94V-0级。     

氨基树脂膨胀型阻燃剂处理环氧树脂的阻燃机理

合成了一种氨基树脂膨胀型阻燃剂(AIFR),将其用于环氧树脂(EP)中。采用热重、红外光谱和扫描电镜研究了阻燃EP的热解性能和阻燃机理。结果表明:AIFR用量为25%时,EP阻燃性能达到UL94V—0级,氧指数28.4%;AIFR使EP热解提前,热解活化能降低,剩炭增加,红外光谱中吸收峰强度减弱;AIFR对EP的热解具有催化成炭作用;AIFR阻燃EP具有很好的膨胀发泡效果,剩炭的连续性、韧性和强度得到了明显改善。     

水滑石对IFR/HDPE复合材料的协效作用

利用熔融共混法制备了水滑石(LDH/)膨胀型阻燃剂(IFR/)高密度聚乙烯(HDPE)复合材料,并对复合材料的力学性能、阻燃性能、热稳定性能和燃烧炭层结构进行了研究。结果表明:LDH对复合材料具有明显的增强作用,在聚磷酸铵/丙三醇/三聚氰胺/HDPE体系中增强幅度最大;LDH能有效提高复合材料的氧指数,且在丙三醇和季戊四醇阻燃复合体系中能有效抑制熔滴和发烟量;LDH可以促进膨胀阻燃体系形成质密多孔炭层并,提高炭层的强度。     

可膨胀石墨/聚磷酸铵协同阻燃聚乙烯的研究

本文进行了可膨胀石墨(EG)/聚磷酸铵(APP)协同阻燃聚乙烯的研究。采用氧指数(LOI)、扫描电镜(SEM)和热重分析(TG)等技术手段对EG/APP阻燃聚乙烯体系进行表征。结果表明,加入APP后,体系氧指数明显提高,热降解速率降低,热稳定性增强。说明EG/APP发挥了协同阻燃作用,形成了致密稳定的膨胀炭层。     

膨胀型无卤阻燃聚乙烯材料的研究

采用膨胀型阻燃剂-聚磷酸铵和季戊四醇(APP/PER)体系对低密度聚乙烯(LDPE)进行阻燃.通过热重分析(TGA)方法研究了成炭促进剂Zeolite(ZEO)对APP/PER和LDPE的催化成炭作用以及影响LDPE/APP/PER材料阻燃性能的各种因素,同时还对APP与PER之间的膨胀成炭反应历程进行了初步探讨.利用混料试验设计方法对LDPE/APP/PER/AEO材料的配方进行了优化设计,得到了使材料阻燃性能达到最好时的APP/PER/ZEO之间的最佳配比.实验结果表明,将APP、PER、与ZEO联用有较好的阻燃协效作用,添加APP/PER/ZEO膨胀型阻燃剂体系可使阻燃聚乙烯材料的氧指数达到29.3.     

硅灰改性膨胀型阻燃剂的阻燃机理

以聚磷酸铵、季戊四醇、尿素为阻燃体系,聚酯树脂为基料,加入不同掺量的硅灰,制备硅灰改性膨胀型阻燃剂.通过锥形量热仪、扫描电子显微镜及热重分析仪,对硅灰改性膨胀型阻燃剂的阻燃性能、微观形貌及阻燃机理进行分析,确定最佳硅灰掺量.结果表明:硅灰掺量为2 wt％时样品的阻燃效果最佳,其可使热释放速率峰值和平均热释放速率值最小,火焰强度最低,耗氧量最少,二氧化碳释放量最少;分析样品燃烧后的微观形貌可知硅灰有助于形成更加致密平滑的炭层,其中硅灰掺量为2 wt％时炭层结构最致密完整;热重结果表明硅灰改性膨胀型阻燃剂具有耐高温性,即硅灰的加入能有效降低失重温度,减少试样质量损失,提高其阻燃性能.     

膨胀石墨在聚乙烯中阻燃协效作用的研究

以膨胀石墨(EG)与聚磷酸铵(APP)复配组成膨胀型阻燃剂，应用于高密度聚乙烯(PE-HD)中。热分析表明APP／FG的添加使得PE-HD材料的热稳定性增强，降解过程变缓，剩炭率增加。氧指数(LOI)结果表明APP／EG具有良好的阻燃协同作用。扫描电镜(SEM)显示APP／EG的加入可使得PE-HD样品生成连续致密的炭层。同时力学性能研究表明APP／EG对材料的力学性能的影响比其它膨胀型阻燃剂要小。     

硅酮粉与复合膨胀阻燃剂协同作用对聚丙烯阻燃性能的影响

研究了硅酮粉、聚磷酸铵(APP)与季戊四醇(PER)组成的复合膨胀阻燃剂(IFR)协同作用对聚丙烯(PP)热降解及阻燃性能的影响。通过TGA、LOI极限氧指数表征了PP材料热降解及阻燃性能。采用扫描电镜(SEM)表征了燃烧后残留炭层的表面形貌。结果表明:在PP燃烧过程中,硅酮粉能促进形成致密的,紧凑的膨胀阻燃炭层。当阻燃剂用量占体系的30%时,在聚丙烯阻燃体系中,硅酮粉与膨胀性IFR阻燃剂协同阻燃效果比单独使用IFR的阻燃效果好。硅酮粉与膨胀性IFR阻燃剂协同阻燃效果最佳用量为:硅酮粉为2%,IFR为28%。     

APP/Sb2O3复合阻燃剂对聚乙烯性能的影响

以低密度聚乙烯(LDPE)和线性低密度聚乙烯(LLDPE)二元共混体系为基础树脂,膨胀型阻燃剂聚磷酸铵(APP)与三氧化二锑(Sb2O3)组成无卤膨胀型阻燃体系,研究APP/Sb2O3复合阻燃剂对复合阻燃体系阻燃性能的影响.结果表明,LDPE/LLDPE为100份,复合阻燃体系中APP/Sb2O3阻燃剂总添加量不低于40份时可达到FV-0阻燃级别;复合阻燃体系的力学性能、流动性能和加工性能均随阻燃剂含量的增加而变差.     

Influence of ultrafine zinc borate on the thermal degradation behavior of a(low‐density polyethylene)/(intumescent flame retardant) system

The thermal degradation behavior of low‐density polyethylene (LDPE), LDPE treated with an intumescent flame retardant (LDPE/IFR), and LDPE treated with an intumescent flame retardant and ultrafine zinc borate (LDPE/IFR/UZB) was studied by (thermal gravimetric)‐(differential thermal) analysis (TG‐DTA) and cone calorimetry. The results of TG‐DTA showed that the initial degradation temperature increased, thermal degradation rate decreased, and the residual char amount increased substantially during the Pyrolysis process when ultrafine zinc borate was introduced into the LDPE/IFR system. The mass‐loss rate (MLR) curves and mass curves obtained by cone calorimetry showed that UZB could decrease the MLR and significantly enhance the residual char amount of LDPE/IFR during the combustion process. The results of Fourier transform infrared spectroscopy implied that a graphite‐like char and aromatic structures containing P‐O‐P, P‐O‐C, and B‐O‐B bonds were formed when LDPE/IFR/UZB was heated at high temperature. Scanning electronic micrographs of residual chars showed that ultrafine zinc borate improved char quality. X‐ray diffraction Studies implied that boron orthophosphate (BPO₄) formed in the residual char may play an important role in improving the structural properties of the char and is responsible for its good quality. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

Effect of ultrafine zinc borate on the smoke suppression and toxicity reduction of a low‐density polyethylene/intumescent flame‐retardant system

The production of smoke, carbon monoxide (CO), and carbon dioxide (CO₂) were investigated with cone calorimetry testing when low‐density polyethylene (LDPE), LDPE treated with an intumescent flame retardant (IFR), and LDPE treated with an IFR and ultrafine zinc borate (UZB) combusted under irradiation. The results of the testing showed that UZB could depress smoke production and reduce the amount of CO and CO₂. The components of the pyrolytic gas and its contents were identified and measured with pyrolysis–gas chromatography/mass spectrometry (Py–GC–MS) when LDPE, LDPE/IFR, and LDPE/IFR/UZB were pyrolyzed at 400°C for 20 s. The Py–GC–MS results implied that UZB had an important influence on the components and contents of the pyrolytic gas of LDPE/IFR. UZB mechanisms of smoke suppression and toxicity reduction with respect to LDPE/IFR are proposed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synergist flame retarding effect of ultrafine zinc borate on LDPE/IFR system

The flame retardancy of low‐density polyethylene (LDPE) treated with complex flame retardant composed of ultrafine zinc borate (UZB) and intumescent flame retardant (IFR) have been investigated by limited oxygen index (LOI), UL‐94 test, thermogravimetric analysis (TGA), cone calorimeter test, scanning electron micrograph (SEM), energy‐dispersive spectrometer (EDS), and X‐ray diffraction (XRD). The results of LOI and UL‐94 test indicate the desired flame retardancy of LDPE is obtained when the mass ratio of UZB to IFR is 4.2 : 25.8 and the complex flame retardant mass content is 30% (based on LDPE). The results of cone calorimeter show that heat release rate (HRR) peak, total heat release (THR), and mass loss of LDPE/IFR/UZB decrease substantially when compared with those of LDPE/IFR. TGA results show that the residue of LDPE/IFR/UZB increases obviously than that of LDPE/IFR when the temperature is above 600°C. SEM indicates the quality of char forming of LDPE/IFR/UZB is superior to that of LDPE/IFR. The results of EDS and XRD indicate that boron orthophosphate (BPO₄) and zinc‐contained compounds are formed in the residual char and these substances may play an important role in stabilizing the intumescent char structure and decrease the degradation speed substantially when subjected to high temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3667–3674, 2007     

超细硼酸锌对LDPE/IFR体系抑烟性能的影响

用锥形量热法研究了超细硼酸锌对膨胀型阻燃低密度聚乙烯(LDPE/IFR)体系燃烧时发烟量和气体(CO、CO2)释放量的影响。结果表明:在超细硼酸锌引入LDPE/IFR体系后,烟产生速率的峰值从0.0427m2/s降低到0.0151m2/s,总烟释放量由1340.95降低为719.6,烟产生速率峰值出现的时间推后,证明了超细硼酸锌具有显著的抑烟作用,同时对LDPE/IFR体系燃烧时产生的CO和CO2也具有显著的抑制作用。     

Synergistic Effects of Nanoporous Nickel Phosphates VSB-1 on an Intumescent Flame-Retardant Low-Density Polyethylene (LDPE) System

Nanoporous nickel phosphates VSB-1 was synthesized by hydrothermal method, and its structure was characterized by X-ray diffraction (XRD), thermogravimetric analyses (TGA) and high resolution transmission electron microscopy (HRTEM). The flame retardancy and thermal behaviour of intumescent flame retardants (IFR) with and without VSB-1 for low-density polyethylene (LDPE) were evaluated by LOI, UL-94 burning test, TGA and cone calorimeter test. With the addition of 2 wt% VSB-1 to LDPE/IFR systems, the LOI value increases from 28.7 to 31, and UL-94 rating raises from V-1 rating to V-0 rating. The results of cone calorimeter show that heat release rate (HRR) peak decrease substantially from 511 KW/m² to 407 KW/m² with 2 wt% VSB-1 in LDPE/IFR systems. The scanning electron microscopy (SEM) indicates the quality of char forming of LDPE/IFR/ VSB-1 is superior to that of LDPE/IFR.     

Synergistic flame‐retardant effect of halloysite nanotubes on intumescent flame retardant in LDPE

Synergistic flame‐retardant effect of halloysite nanotubes (HNTs) on an intumescent flame retardant (IFR) in low‐density polyethylene (LDPE) was investigated by limited oxygen index (LOI), vertical burning test (UL‐94), thermogravimetric analysis (TGA), cone calorimeter (CC) test, and scanning electronic microscopy (SEM). The results of LOI and UL‐94 tests indicated that the addition of HNTs could dramatically increase the LOI value of LDPE/IFR in the case that the mass ratio of HNTs to IFR was 2/28 at 30 wt % of total flame retardant. Moreover, in this case the prepared samples could pass the V‐0 rating in UL‐94 tests. CC tests results showed that, for LDPE/IFR, both the heat release rate and the total heat release significantly decreased because of the incorporation of 2 wt % of HNTs. SEM observations directly approved that HNTs could promote the formation of more continuous and compact intumescent char layer in LDPE/IFR. TGA results demonstrated that the residue of LDPE/IFR containing 2 wt % of HNTs was obviously more than that of LDPE/IFR at the same total flame retardant of 30 wt % at 700°C under an air atmosphere, and its maximum decomposing rate was also lower than that of LDPE/IFR, suggesting that HNTs facilitated the charring of LDPE/IFR and its thermal stability at high temperature in this case. Both TGA and SEM results interpreted the mechanism on the synergistic effect of HNTs on IFR in LDPE, which is that the migration of HNTs to the surface during the combustion process led to the formation of a more compact barrier, resulting in the promotion of flame retardancy of LDPE/IFR. In addition, the mechanical properties of LDPE/IFR/HNTs systems were studied, the results showed that the addition of 0.5–2 wt % of HNTs could increase the tensile strength and the elongation at break of LDPE/IFR simultaneously. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40065.     

Synergic flame retardancy mechanism of montmorillonite in the nano-sized hydroxyl aluminum oxalate/LDPE/EPDM system

Nano-sized hydroxyl aluminum oxalate (nano-HAO) and montmorillonite (MMT) were mixed into low density polyethylene (LDPE)/ethylene propylene diene rubber (EPDM) system via melt compounding method. By means of LOI and UL94 horizontal burning tests, MMT and nano-HAO together exhibited better performance on flame-retarding LDPE/EPDM composites than how they performed individually, which proved that there existed a synergistic effect between MMT and nano-HAO on flame retardancy. Furthermore, through the analysis of Fourier transform IR spectra (FTIR), scanning electron microscope (SEM), and the thermogravimetric and differential thermal analysis (TG-DTA), the mechanism of the synergistic flame retardance was proposed as when MMT was added into nano-HAO/LDPE/EPDM composites, a laminated structure formed in the char layer and thus the transmission speeds of heat, oxygen, flammable mass and vapor were adjusted. So the process of combustion was retarded owing to lack of oxygen and heat.     

硼酸锌在LDPE阻燃中的协效作用

阻燃协效剂硼酸锌加入无卤及有卤阻燃聚乙烯中,对其性能进行了测试,包括力学性能、阻燃性能。结果表明:硼酸锌对无卤及有卤体系都具有良好的协同效应,加入硼酸锌的体系是高效阻燃体系。     

Effect of zinc borate on the fire and thermal degradation behaviors of a poly(3-hydroxybutyrate-co-4-hydroxybutyrate)-containing intumescent flame retardant

The aim of this study was to investigate the effect of zinc borate (ZnB) on the fire and thermal degradation behaviors of a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3,4)HB]-containing intumescent flame retardant (IFR). The IFR system was composed of ammonium polyphosphate, pentaerythritol, and melamine. The fire properties of P(3,4)HB/IFR/ZnB blends were evaluated by limited oxygen index, Underwriters Laboratories 94, microscale combustion calorimetry (MCC), and cone calorimetry (CONE) testing. The results of MCC and CONE show that the peak heat release rate, which is an important indicator of material fire hazard, of P(3,4)HB/IFR decreased when a small amount of the IFR was substituted by ZnB. The thermal degradation behavior of the P(3,4)HB/IFR/ZnB blends were measured by thermogravimetric analysis and thermogravimetric analysis–infrared (TG–IR) spectrometry. The data of TG–IR showed that the flammable gas products of P(3,4)HB released during the thermal degradation process were greatly decreased. Scanning electron microscopy analysis revealed that more compact char residues were observed with the incorporation of ZnB. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

HDPE/LDPE复合交联物的热降解研究

采用热重分析仪（TG）考察了高密度聚乙烯（HDPE）／低密度聚乙烯（LDPE）复合交联物的热稳定性。结果显示，HDPE／LDPE复合交联物的热稳定性低于HDPE／LDPE共混物。FTIR分析证实，交联反应使聚乙烯（PE）的支化程度提高，取代基的位阻效应在一定程度上影响了PE的热降解过程。在N2气氛下，HDPE／LDPE共混物及交联物的热降解过程均为一步降解反应。Kissinger法求解HDPE／LDPE共混物及其复合交联物的热降解活化能发现，LDPE质量分数在20％～30％之间变化时，HDPE／LDPE交联物的热降解过程对温度的敏感性发生了突变。