无卤阻燃ABS/TPU复合材料阻燃性能的研究

采用了微胶囊红磷(MRP)、氢氧化镁(MH)、聚硅氧烷组成复合阻燃剂,对丙烯腈-丁二烯-苯乙烯(ABS)/热塑性聚氨酯(TPU)合金进行改性,获得了环保型阻燃ABS/TPU复合材料。对该复合材料进行了阻燃性能、热稳定性测试和炭层形貌分析。结果表明,当复合阻燃剂MRP/MH质量比为1/1且添加量为16份时,复合材料的极限氧指数(LOI)为25.7%,垂直燃烧性能通过FV-0级;TPU结构中因含氧,有利于MRP/MH阻燃体系阻燃;添加6份聚硅氧烷,复合材料垂直燃烧级别达到FV-0级,聚硅氧烷燃烧过程中通过改变炭层形貌,提高阻燃性。     

高抗冲聚苯乙烯/微胶囊红磷/膨胀石墨阻燃材料的制备及性能研究

用熔融混合法制备了高抗冲聚苯乙烯(HIPS)/微胶囊红磷(MRP)/膨胀石墨(EG)无卤阻燃材料.用氧指数法、垂直燃烧及热重分析等方法研究了EG/MRP复配阻燃剂对高抗冲聚苯乙烯的阻燃作用,并对阻燃前后的HIPS复合阻燃材料进行了红外分析。结果表明,MRP和EG复配,可以使HIPS的氧指数提高到27%,垂直燃烧级别达到FV-0(1.5 mm);但是MRP与EG之间不存在协同阻燃效应;复配阻燃剂的作用机理为凝聚相阻燃机理,抗滴落剂的加入可以有效阻止材料燃烧时的滴落,提高材料的阻燃级别。     

Mg(OH)_2-Al(OH)_3-微胶囊红磷协同阻燃POE的研究

以氢氧化镁(MH)、氢氧化铝(ATH)为无卤阻燃剂,微胶囊红磷(MRP)为阻燃增效剂,通过共混挤出制备了一系列的阻燃聚烯烃弹性体(POE)复合材料。采用垂直燃烧、极限氧指数、热失重、傅里叶红外、微型量热分析等方法研究了其阻燃性能及阻燃机理。研究表明,同MH/POE和ATH/POE相比,MH/ATH/POE有较好的阻燃协效性,氧指数达到25.0%,残炭量达到31.7%,但垂直燃烧性能较差(测试无级别)。继续加入6份MRP后,体系的阻燃性能明显提高,其氧指数上升至27.5%,残炭量高达35.2%,垂直燃烧达到V-0级。表明MH/ATH和MRP对POE具有显著的协同阻燃作用。FTIR和TGA实验结果显示,MRP/MH/ATH/POE复合材料燃烧后生成了磷酸及其衍生物,增强了体系的成炭能力,促进了凝聚相阻燃效果,MRP阻燃机理主要表现为凝聚相阻燃。     

几种含磷阻燃剂对高抗冲聚苯乙烯/氢氧化镁复合材料燃烧性能的影响

分别将微胶囊红磷(MRP)、聚磷酸铵(APP)、间苯二酚双(二苯基磷酸酯)(RDP)通过熔融共混方法加入到高抗冲聚苯乙烯/氢氧化镁(HIPS/MH)复合材料中,制备了一系列含有不同含磷阻燃剂的HIPS/MH复合材料。采用垂直燃烧实验、极限氧指数实验(LOI)和锥形量热仪测试(Cone)研究了复合材料的燃烧性能。结果表明:与HIPS/MH复合材料相比,MRP阻燃剂用量为6.7%时,HIPS/MH/MRP复合材料的垂直燃烧级别由原来的无级别升至V-0级,LOI由原来的21.3%提高到23.5%,热释放速率峰值(PHRR)由271 k W/m~2降至175k W/m~2,平均热释放速率(AHRR)由134 k W/m~2降低到81 k W/m~2,总热释放量(THR)由111 MJ/m~2下降到64MJ/m~2,表明MRP与MH对HIPS有非常明显的协同阻燃作用。相比之下,APP和RDP对HIPS/MH复合材料的阻燃性能无显著影响,这两种含磷阻燃剂与MH之间无协同阻燃作用。此外,HIPS/MH/MRP复合材料具有良好的加工性能。     

LLDPE/EVA/改性MH/MRP阻燃体系的研究

选用乙烯-醋酸乙烯共聚物/改性氢氧化镁/微胶囊红磷(EVA/改性MH/MRP)为复合阻燃体系,研究体系的力学性能及阻燃性能,并通过扫描电镜观察材料燃烧后炭层的表面形貌。结果表明:当LLDPE/EVA/改性MH/MRP添加比例为60:40:70:10时,拉伸强度为11.3 MPa,断裂伸长率为353%,氧指数为31.4%,垂直燃烧试验通过UL 94V-0级,体系具有良好的阻燃协效作用和力学相容性。     

原位共聚合改性HIPS/氢氧化镁复合材料的性能

采用乙烯基硅烷在氢氧化镁(MH)表面引入乙烯基后与苯乙烯原位聚合,制备苯乙烯原位共聚合改性MH。将改性前后的MH、微胶囊红磷(MRP)、高抗冲聚苯乙烯(HIPS)按不同配比熔融复合制备HIPS/MH和HIPS/MH/MRP复合材料。研究了复合材料的力学性能和阻燃性能。结果表明:改性后的MH能显著提高复合材料的冲击强度。改性前后的MH与MRP的协同阻燃效应使HIPS/MH复合材料极限氧指数提高到28.9%,UL 94垂直燃烧达到V-0级。MH与MRP的协同作用增加了HIPS/MH复合材料的点燃难度,有效抑制了HIPS的热释放速率和烟释放速率,对HIPS起到良好的阻燃作用。     

阻燃热塑性聚酯弹性体复合材料制备及性能

以二乙基亚膦酸铝盐(AlPi)和三聚氰胺氰脲酸盐(MCA)为阻燃剂,添加到热塑性聚酯弹性体(TPEE)中,采用挤出造粒方法制备出高性价比的阻燃TPEE复合材料。首先采用热失重分析仪研究了两种阻燃剂的热稳定性,进一步采用热失重分析、极限氧指数测试、垂直燃烧测试、力学性能测试以及扫描电子显微镜等对阻燃TPEE材料的热稳定性、阻燃性能、燃烧性能、力学性能以及复合材料的微观形貌进行了研究。结果表明,在相同阻燃剂用量下,添加AlPi的阻燃复合材料的阻燃效果、力学性能均优于添加MCA的阻燃复合材料,采用AlPi与MCA复配使用制备的阻燃TPEE复合材料的阻燃效果、力学性能介于二者之间,当TPEE,AlPi和MCA用量分别为83%,10%和5%时,阻燃复合材料的拉伸强度为24.19 MPa,断裂伸长率为515%,极限氧指数为30%,垂直燃烧测试达到V–0级。AlPi与MCA复配使用可提升阻燃TPEE材料的成炭性能和高温热稳定性。     

HDPE/PA6/MRP共混物阻燃性能研究

用微胶囊化红磷(MRP)作为阻燃剂,利用双螺杆挤出机制备了阻燃HDPE/MRP共混物,并首次使用点燃氧指数和燃烧氧指数来表征它们的阻燃性能。结果表明:添加少量的PA6可提高HDPE/MRP复合材料的阻燃效果,固定PA6与MRP的添加总量为15%,且在HDPE∶PA6∶MRP=85∶4∶11时,其极限氧指数最大,为22.1%;在固定MRP含量的情况下,随PA6含量的增加,HDPE/PA6/MRP复合材料的阻燃性增强。     

协效阻燃剂对PE-HD/Ca(OH)2复合材料阻燃性能影响的研究

选用聚磷酸铵（APP）、三氧化钼（MoO3）、可膨胀石墨（EG）及微胶囊红磷（MRP）等作为高密度聚乙烯/氢氧化钙[PE-HD/Ca(OH)2]复合材料的协效阻燃剂,对PE-HD/Ca(OH)2复合材料的力学性能和阻燃性能进行了较深入的研究,并采用热重法研究了PE-HD/Ca(OH)2复合材料在氮气环境中的热失重过程。结果表明,少量协效剂（APP,MoO3,EG,MRP）的引入, 使PE/Ca(OH)2复合材料的氧指数分别比单独添加35 %Ca(OH)2时提高了2.38%、4.76%、7.14%和26.19%,且使其热氧化降解过程中生成更多的结实而稳定的炭层,起到一定的阻燃增效作用。     

可膨胀石墨/聚磷酸铵协同阻燃聚苯乙烯的研究

将可膨胀石墨(EG)与聚磷酸铵(APP)复配并添加至聚苯乙烯(PS)基体中,制备了PS/EG/APP阻燃复合材料。通过极限氧指数(LOI)、水平垂直燃烧(UL 94)测试,以及热重分析(TG)和扫描电镜分析(SEM)对PS/EG/APP阻燃复合材料的阻燃性能和热稳定性进行了检测,并优化了该材料配方。结果表明:复合阻燃剂EG/APP的加入,使得体系的LOI值与热稳定性均明显提高。其中当复合阻燃剂EG/APP的添加量为30 phr,且质量比为3:1时,阻燃体系的LOI值可达到31.8%,而单独添加同量EG或APP的阻燃体系,其LOI值仅为29%和20.8%,这说明EG与APP之间存在协同效应。     

Enhanced flame retardancy,smoke suppression,and acid resistance of polypropylene/magnesium hydroxide composite by expandable graphite and microencapsulated red phosphorus

Low flame retardant efficiency and poor acid resistance of filled polymer composites are two main drawbacks of magnesium hydroxide (MH) as a flame retardant (FR). To solve these problems, expandable graphite (EG) and microencapsulated red phosphorus (MRP) were introduced into polypropylene/magnesium hydroxide (PP/MH) composite by melt compounding. The obtained PP/MH/EG/MRP quadruple composite was studied regarding its fire behavior as well as acid resistance. Obvious flame retardant synergism among MH, EG, and MRP is found in PP, which diminishes the loading of FR from 63.0 to 37.5 wt% to obtain V-0 rating in UL-94 test and low smoke release. Compact intumescent char with high thermo-oxidative stability was generated on composite surface, which plays a vital role in flame retardancy. The removal of MH by acid erosion on PP/MH/EG/MRP composite surface does not affect production of intumescent char and fire behavior of this composite. The composite displays good fire retardancy, smoke inhibition, and acid resistivity concurrently. This article renders an easy and cheap route to overcome the main faults of MH.     

Synergistic effects of exfoliated LDH with some halogen‐free flame retardants in LDPE/EVA/HFMH/LDH nanocomposites

The synergistic effects of exfoliated layered double hydroxides (LDH) with some halogen‐free flame retardant (HFFR) additives, such as hyperfine magnesium hydroxide (HFMH), microencapsulated red phosphorus (MRP), and expandable graphite (EG), in the low‐density polyethylene/ethylene vinyl acetate copolymer/LDH (LDPE/EVA/LDH) nanocomposites have been studied by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal analysis (TGA and DTG), mechanical properties, limiting oxygen index (LOI), and UL‐94 tests. The XRD results show that EVA as an excellent compatilizer can promote the exfoliation of LDH and homogeneous dispersion of HFMH in the LDPE/EVA/HFMH/LDH nanocomposites prepared by melt‐intercalation method. The TEM images demonstrate that the exfoliated LDH layers can act as synergistic compatilizer and dispersant to make the HFMH particles dispersed homogeneously in the LDPE matrix. The results from the mechanical, LOI, and UL‐94 tests show that the exfoliated LDH layers can also act as the nano‐enhanced and flame retardant synergistic agents and thus increase the tensile strength, LOI values, and UL‐94 rating of the nanocomposites. The morphological structures of charred residues observed by SEM give the positive evidence that the compact charred layers formed from the LDPE/EVA/HFMH/LDH nanocomposites with the exfoliated LDH layers play an important role in the enhancement of flame retardant and mechanical properties. The TGA and DTG data show that the exfoliated LDH layers as excellent flame retardant synergist of MRP or EG can apparently increase the thermal degradation temperature and the charred residues after burning. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synergistic effects of expandable graphite with magnesium hydroxide on the flame retardancy and thermal properties of polypropylene

In this study, the flammability characterization and synergistic effects of different particle size of expandable graphite (EG) with modified magnesium hydroxide (MH) in flame‐retardant polypropylene (PP) composites were studied by limiting oxygen index (LOI), UL‐94 test, thermogravimetric analysis (TGA), and fourier transform infrared (FTIR) spectroscopy. The results showed that the particle size of EG had a great effect on the flammability of the PP/MH/EG composites. The EG2 with smaller particle size could apparently increase the LOI value and improved the UL‐94 flammability properties rating of the PP composites. The data obtained from the TGA and FTIR curves indicated that the thermo‐oxidative stability of PP/MH/EG composites increased with decreasing particle size of EG. And the smaller the particle size of EG, the higher the residues of the composite. POLYM. ENG. SCI., 47:1756–1760, 2007. © 2007 Society of Plastics Engineers     

Combustion characteristics and synergistic effects of red phosphorus masterbatch with expandable graphite in the flame retardant HDPE/EVA composites

In this work, the flammability behaviors and synergistic effects of red phosphorus masterbatch (RPM) with expandable graphite (EG) in flame‐retardant high‐density polyethylene/ethylene vinyl‐acetate copolymer (HDPE/EVA) composites have been investigated by limiting oxygen index (LOI), UL‐94 test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), Fourier‐transform infrared (FTIR) and scanning electron microscopy (SEM). The data obtained from LOI, UL‐94 test and CCT showed that suitable amount of RPM had synergistic effects with EG in the HDPE/EVA/EG/RPM composites. The addition of RPM greatly increased the LOI values by 3.4%, obtained UL‐94 V‐0 rating, decreased the heat release rates and total heat release, and prolongated the ignition time when 6.7 phr RPM substituted for EG in the HDPE/EVA/EG/RPM composites. The data from TGA and FTIR spectra also indicated the synergistic effects of RPM with EG considerably enhanced the thermal degradation temperatures. The morphological observations after UL‐94, CCT, and SEM images presented positive evidences that the synergistic effects took place for RPM with EG, and the flame‐retardant mechanism has been changed in flame‐retardant HDPE/EVA/EG/RPM composites. The formation of stable and compact charred residues promoted by RPM acted as effective heat barriers and thermal insulations, which improved the flame‐retardant performances and prevented the underlying polymer materials from burning. POLYM. ENG. SCI., 55:2884–2892, 2015. © 2015 Society of Plastics Engineers     

阻燃剂对热固性酚醛树脂阻燃性能影响的研究

通过氧指数、垂直燃烧等级及产烟率测定研究了氢氧化铝(ATH)、氢氧化镁(MH)、膨胀石墨(EG)、膨胀型阻燃剂(IFR)等以单一或协同复配的形式对酚醛树脂(PF)体系阻燃性能的影响,并采用差热分析(DTA)对体系的微观热行为进行了研究。结果表明,放热量最小的体系为ATH/MH/EG/PF,ATH/MH/EG/IFR/PF体系的氧指数最大,达到96。ATH/MH/PF体系的产烟率最低(72%)。添加阻燃剂后,体系的垂直燃烧等级可提高到UL94V-0级。     

Flame‐retardant and thermal degradation mechanism of low‐density polyethylene modified with aluminum hypophosphite and microencapsulated red phosphorus

Aluminum hypophosphite (AHP), a novel flame retardant, was used to improve the flame retardancy of low‐density polyethylene (LDPE) with microencapsulated red phosphorus (MRP). The synergistic effect between MRP and AHP was investigated by the limiting oxygen index (LOI), vertical burning test (UL‐94), and thermogravimetric analysis. When the contents of MRP and AHP were 10 and 30 phr, the LOI of LDPE/10MRP/30AHP composite was 25.5%, and it passed the UL‐94 V‐0 rating (the number before “MRP” and “AHP” is the loading of MRP and AHP, In LDPE/10MRP/30AHP, the content of the LDPE, MRP and AHP is 100phr, 10phr and 30phr, where phr refers to parts per hundreds of resin). The results of cone calorimetry testing show that the heat release rate of the composites was significantly reduced, and the strength of the char layer improved when the loading of AHP increased. The thermal stability of the LDPE/10MRP/30AHP composite was enhanced. The structure of the char was investigated by Fourier transform infrared spectrometry and scanning electron microscopy/energy‐dispersive spectrometry. The results indicate that AHP promoted the formation of stable char. This research provided a good way to prepare flame‐retardant materials with a halogen‐free flame retardant and contributed to environmental protection. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43225.     

线型酚醛与微胶囊红磷阻燃ABS的研究

采用线型酚醛(Novolac)与微胶囊红磷(MRP)复配阻燃,制备了无卤阻燃丙烯腈-丁二烯-苯乙烯(ABS)复合材料。研究了Novolac/MRP质量比和用量对阻燃ABS性能的影响。研究结果表明:Novolac/MRP的质量比为3/2,总量为15%(质量分数)时,可以制备极限氧指数(LOI)为26.7%,垂直燃烧(UL94)V-0级的无卤阻燃ABS;Novolac的酚羟基与MRP燃烧产生的聚磷酸在高温下发生的脱水成炭反应减缓了ABS的分解;SEM炭层形貌分析表明:Novolac/MRP复合阻燃ABS材料燃烧表面形成了平整、致密的炭层,该炭层能够有效地隔绝燃烧过程所产生的易燃气体及热量,起到较好的阻燃效果。     

磷氮复配无卤阻燃聚苯醚合金的研究

采用固体阻燃剂间苯二酚双[二(2,6-二甲苯基)磷酸酯](RXP)及其与三聚氰胺氰脲酸盐(MCA)的复配阻燃剂,制备了无卤阻燃聚苯醚/高抗冲聚苯乙烯/苯乙烯-丁二烯-苯乙烯热塑性弹性体(PPE/PS-HI/SBS)合金,通过氧指数、水平垂直燃烧、扫描电子显微镜、力学性能等测试分析方法,考察了PPE/PS-HL/SBS合...     

Preparation of expandable graphite with silicate assistant intercalation and its effect on flame retardancy of ethylene vinyl acetate composite

A halogen‐free intumescent flame retardant expandable graphite composite (EG), with an initial expansion temperature of 202°C and expansion volume of 517 mL g⁻¹, was successfully prepared via a facile two‐step intercalation method, i.e. using KMnO₄ as oxidant and H₂SO₄, Na₂SiO₃·9H₂O as intercalators. The prepared EG flame retardant was characterized by field emission scanning electron microscope, X‐ray diffraction spectroscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. Furthermore, flame retardancy and thermal property of various ethylene vinyl acetate copolymer (EVA) composites, including EVA/EG and EVA/EG/APP (ammonium polyphosphate) specimens, were studied through limiting oxygen index instrument (LOI), vertical combustion UL‐94 rating, thermal gravimetric and differential thermal analysis. The results indicate that the EVA/EG and EVA/EG/APP composites exhibit a better flame retardancy. Addition of EG at a mass fraction of 30% leads LOI of 70EVA/30EG composite improved to 28.7%. Even more, the synergistic effect between EG and APP improves the LOI of 70EVA/10APP /20EG composite to 30.7%. This synergistic efficiency is attributed to the formation of compact and stable layer‐structure, and the prepared EG can make EVA composite reach the UL‐94 level of V‐0. POLYM. COMPOS., 36:1407–1416, 2015. © 2014 Society of Plastics Engineers