Regulating the Localization of Intumescent Flame Retardant for Improving the Flame Retardancy of Ethylene-vinyl Acetate Copolymer Using Polyamide 6 as a Charring Agent

Polyamide 6 (PA6) was employed as a charring agent of intumescent flame retardant (IFR) to improve the flame retardancy of ethylene-vinyl acetate copolymer (EVA). Different processing procedures were used to regulate the localization of IFR in the EVA matrix. Localizations in which IFR was dispersed in the PA6phase or in the EVA phase were prepared. The effect of the localization of IFR on the flame retardancy of EVA was investigated. The limited oxygen index (LOI), vertical burning (UL 94) and cone calorimeter test (CCT)showed that the localization of IFR in the EVA matrix exhibited a remarkable influence on the flame retardancy.Compared with EVA/IFR, a weak improvement in the flame retardancy was observed in the EVA/PA6/IFR blend withthe localization of IFR in the PA6 phase. When IFR was regulated from the PA6 phase to the EVA matrix,a remarkable increase in the flame retardancy was exhibited. The LOI was increased from 27.8%to 32.7%, and the UL 94 vertical rating was increased from V-2 to V-0. Moreover, an approximately 41.36%decrease in the peak heat release rate was exhibited. A continuous and compact intumescent charring layer that formed in the blends with the localization of IFR in the EVA matrix should be responsible for its excellent flame retardancy.

Synthesis and thermal stability of a novel phosphorus-nitrogen containing intumescent flame retardant

A novel phosphorus-nitrogen containing intumescent flame retardant （P-N IFR） was prepared via the reaction of dichlor-opentate with N-methylaniline. The structure of the product was confirmed by ^1H NMR, ^31p NMR, MS and IR. TGA analysis showed it has effective thermal stability.

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.

Synergistic effect of MXene on the flame retardancy and thermal degradation of intumescent flame retardant biodegradable poly(lactic acid)composites

The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt%-12.0 wt%IFR and PLA together.The results of limiting oxygen index(LOI)and vertical burning(UL-94)discover that the combination of 0.5 wt%MXene and 11.5 wt%IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%.The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate(HRR)in cone calorimeter tests(CCTs).Furthermore,the carbon residues after CCTs were characterized by scanning electron microscope(SEM),laser Raman spectroscopy(LRS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/MXene composite materials’ability to produce a dense barrier layer to resist burnout during thermal degradation.

Intumescent Flame-retardant Modification of Polypropylene/Carbon Fiber Composites

To improve the flame resistance of polypropylene(PP)/carbon fiber(CF)composite materials,triazine char-forming agent(TCA)was compounded with ammonium polyphosphate(APP)or modified APP(CS-APP)in a 2:1 ratio to prepare intumescent flame retardant(IFR)and the modified intumescent flame retardant(CS-IFR)in this paper.Flame retardancy and thermal degradation behaviors of the composites modified by IFR and CS-IFR were characterized by Fourier Transform Infrared(FTIR),contact angle measurement,oxygen index(OI),vertical burning tests(UL-94),thermogravimetric analyer(TGA),and thermogravimetric analyzer coupled with Fourier transform infrared(TG-FTIR).It was found that 25.0 phr of IFR and 24.0 phr of CS-IFR could improve the LOI value of PP/CF composites to 28.3%and 28.9%,respectively.At the same time,a UL-94 V-0 rating was achieved.The experimental results show that the IFR and CS-IFR prepared could effectively improve the flame retardancy and thermostability of PP/CF composites,and they would greatly expand the application range of PP/CF composite materials.

Synthesis and Application of Novel Triazine-Based Charring-Foaming Agents in Intumescent Flame Retardant Polypropylene

Three novel triazine-based charring-foaming agents (M2-CFA, M4-CFA, and M6-CFA) were synthesized successfully with only water as the solvent and were characterized by FT-IR and thermal gravimetric analysis (TGA). These three charring-foaming agents and the byproduct 944-by were employed to study the effectiveness of the novel intumescent flame retardant dopant on the fire retardancy of polypropylene(PP) investigated through UL-94 and limiting oxygen index (LOI) tests. TGA results showed that the M4-CFA presented good char formation ability (char residue: 26.8% at 700 °C). It was found that the sample with a 2/1 mass ratio of APP to M4-CFA exhibited the best flame retardancy among all the PP composites: 35.5% LOI and a V-0 rating of UL-94. Additionally, the microstructure and morphology of char residues were further studied by XRD, Raman spectroscopy and SEM. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

Effect of MMT on Flame Retardancy of PLA/IFR/LDH Composites

Nano filler synergistic intumescent flame retardant(IFR)system is an effective way to improve the flame retardant properties of polymer.In this study,the effects of montmorillonite(MMT)on the flame retardant properties of polylactic acid/layered double hydroxides(PLA/LDH)and PLA/IFR/LDH were investigated.The results show that both LDH and LDH/IFR can reduce the peak heat release rate(HRR)of PLA and prolong the combustion time of PLA;When a proportionate MMT is introduced into PLA/LDH and PLA/IFR/LDH systems,respectively,MMT will not only affect the degradation process of PLA composites during combustion,but also the PLA composites can form a more stable carbon layer during combustion,which could decrease the peak HRR and prolong combustion time of PLA composite.Furthermore,when 0.5 wt%MMT is incorporated,the peak HRR of LDH/IFR/LDH composite is reduced by 16.17%and the combustion time is prolonged by about 70 s.This study can provide an opportunity to further optimize the properties of intumescent flame retardant polymer.

AN S-AND P-CONTAINING FLAME RETARDANT FOR POLYPROPYLENE

A novel charring agent,bis(1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane) phenylphosphine sulfide (BCPPS),has been synthesized,and it is combined with ammonium polyphosphate (APP) and melamine phosphate (MP) to impart flame retardance and dripping resistance for polypropylene (PP).The fire performance of the treated PP is investigated by limiting oxygen index (LOI),vertical burning test (UL-94) and cone calorimeter,and the thermal stability and thermal oxidative stability of the composite...

利用OVMT和CMS提高IFR/H-PP复合材料的阻燃和力学性能

以打包盒PP废塑料(H-PP)为原料、膨胀型阻燃剂(IFR)为阻燃剂、有机蛭石(OVMT)和碳微球(CMS)为阻燃协效剂,制备阻燃H-PP复合材料,对复合材料的极限氧指数(LOI)、UL 94阻燃等级和力学性能进行测试,并且,采用TG、锥形量热仪和SEM进行分析。结果表明,OVMT和IFR在H-PP中具有协同阻燃效果,当H-PP中OVMT含量为4%、IFR含量为24%时,复合材料的LOI值为29.8%,阻燃级别达到UL 94 V-0级,OVMT提高了IFR/H-PP的力学性能;CMS和IFR在H-PP中具有协同阻燃效果,CMS能提高IFR/H-PP的力学性能;在IFR/H-PP中同时加入OVMT和CMS,复合材料的阻燃和力学性能均得到提高,2-OVMT/2-CMS/24-IFR/H-PP的LOI为32.4%,阻燃级别达到UL 942.0 mm V-0级,其拉伸强度、弯曲模量、弯曲强度和缺口冲击强度分别为22.5、1132.1、26.2 MPa和3.8 kJ/m^(2),与28-IFR/H-PP相比,分别提高了11.9%、0.3%、8.3%和31.0%。

SYNERGISTIC EFFECTS OF LAYERED DOUBLE HYDROXIDE WITH PHOSPHORUS-NITROGEN INTUMESCENT FLAME RETARDANT IN PP/EPDM/IFR/LDH NANOCOMPOSITES

Synergistic effects of layered double hydroxide （LDH） with intumescent flame retardanct （IFR） of phosphorusnitrogen （NP） compound in the polypropylene/ethylene-propylene-diene/IFR/LDH （PP/EPDM/IFR/LDH） nanocomposites and related properties were studied by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, limiting oxygen index （LOI）, UL-94 test, cone calorimeter test （CCT） and thermo-gravimetric analysis （TGA）. The XRD and TEM results show that the intercalated and/or exfoliated nanocomposites can be obtained by direct melt-intercalation of PP/EPDM into modified LDH and that LDH can promote the IFR additive NP to disperse more homogeneously in the polymer matrix. The SEM results provide positive evidence that more compact charred layers can be obtained from the PP/EPDM/NP/LDH sample than those from the PP/EPDM/LDH and PP/EPDM/NP samples during burning. The LOI and UL-94 rating tests show that the synergetic effects of LDH with NP can effectively increase the flame retardant properties of the PP/EPDM/NP/LDH samples. The data from the CCT and TGA tests indicate that the PP/EPDM/NP/LDH samples apparently decrease the HRR and MLR values and thus enhance the flame retardant properties and have better thermal stability than the PP/EPDM/LDH and PP/EPDM/NP samples.

Synergistic effects of zeolitic imidazolate frameworks(ZIFs)with different transition metals on intumescent flame-retarded polypropylene composites:A comparative study

The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither efficient in developing a thermally stable char layer nor reducing the release of toxic byproducts during polymer combustion.In this work,we aim to discuss the effects of zeolitic imidazolate frameworks(ZIFs)on synergistically improving the flame retardancy behaviors in polypropylene(PP)composites,including thermal degradation(evolved gas analysis),free radical reactions in the gaseous phase(in-situ chemiluminescent image analysis),and carbonaceous structure in the condensed phase(micro-morphology and composition analysis).It is found that the transition metals in ZIFs can catalytically accelerate the crosslinking reaction at a lower initial temperature and decrease the amount of hydrocarbon volatiles in the gaseous phase.Once ignited,the embedded ZIFs can firstly bridge adjacent phosphorus chains in the polymer matrix to expand crosslinking degrees and then they are anchored in the developed N-doped phospho-carbonaceous networks after pyrolysis.As a result,more compact char residue structures are observed in the condensed phase for ZIF-reinforced composites.For example,by replacing 2 wt%of IFR with ZIF-67,the peak heat release rate,peak smoke production rate,and peak CO production rate are reduced by 69%,80%,and 72%,respectively,when compared to the conventional composite.These results indicate an excellent solution to resolve inherent fire hazards associated with IFRs in polymers and achieve necessary efficiency for industrial applications.It also provides a new strategy for determining flammability characteristics and combustion mechanisms of polymer composites using in-situ chemiluminescence analysis.

白泥填料在膨胀阻燃环氧树脂中的协效阻燃和抑烟作用

为实现氨碱白泥的资源化利用,以氨碱白泥为原料,通过烘干、粉碎和表面改性制备白泥填料,并将其作为阻燃协效剂应用于膨胀阻燃环氧树脂,系统研究了白泥填料对膨胀阻燃环氧树脂的阻燃性能、抑烟性能和成炭能力的影响。结果表明,添加白泥填料能够显著降低膨胀阻燃环氧树脂的热释放和生烟量,表现出优异的协效阻燃和抑烟作用。当添加5%烷基化白泥填料时,阻燃和抑烟效率最高,峰值热释放速率和峰值生烟速率降低至234.6 kW/m^(2)和0.048 m^(2)/s,极限氧指数提高到30.5%。此外,白泥填料具有优异的协效成炭作用,添加5%烷基化白泥填料可以促进膨胀阻燃环氧树脂生成更多的芳香结构和含磷的交联结构,增强炭层的致密性和隔热隔质性,提高炭层质量,在700℃下残炭量达到24.5%。

Synergistic Effects of Aluminum Hypophosphite on Intumescent Flame Retardant Polypropylene System

The effects of aluminum hypophosphite（AHP） as a synergistic agent on the flame retardancy and thermal degradation behavior of intumescent flame retardant polypropylene composites（PP/IFR） containing ammonium polyphosphate（APP） and triazine charring-foaming agent（CFA） were investigated by limiting oxygen index（LOI）, UL-94 measurement, thermogravimetric analysis（TGA）, cone calorimeter test（CONE）, scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）. It was found that the combination of IFR with AHP exhibited an evident synergistic effect and enhanced the flame retardant efficiency for PP matrix. The specimens with the thickness of 0.8 mm can pass UL-94 V-0 rating and the LOI value reaches 33.5% based on the total loading of flame retardant of 24 wt%, and the optimum mass fraction of AHP/IFR is 1：6. The TGA data revealed that AHP could change the degradation behavior of IFR and PP/IFR system, enhance the thermal stability of the IFR and PP/IFR systems at high temperatures and promote the char residue formation. The CONE results revealed that IFR/AHP blends can efficiently reduce the combustion parameters of PP, such as heat release rate（HRR）, total heat release（THR）, smoke production rate（SPR） and so on. The morphological structures of char residue demonstrated that AHP is of benefit to the formation of a more compact and homogeneous char layer on the materials surface during burning. The analysis of XPS indicates that AHP may promote the formation of sufficient char on the materials surface and improve the flame retardant properties.

阻燃丙烯酸树脂涂料的制备及其性能

为解决丙烯酸树脂在使用过程中存在阻燃性能低的问题,通过超声和机械搅拌相结合的方法在丙烯酸树脂乳液中加入由聚磷酸铵(APP)、季戊四醇(PER)和三聚氰胺(MEL)以不同配比复合而成的膨胀型阻燃剂(IFR),制得阻燃丙烯酸树脂涂料(PA-IFR)。利用红外光谱仪、X射线衍射仪、铅笔硬度计和极限氧指数仪对PA-IFR的化学结构、透光率、硬度以及阻燃性能进行测试。结果表明:当膨胀型阻燃剂的质量分数为30%,APP/PER/MEL的配方比为2∶1∶1时,PA-IFR的硬度达到5H,极限氧指数LOI值达32.6%,属于难燃材料。

聚苯胺-碳化硅复合材料在膨胀型防火涂料中的应用

膨胀型防火涂料在阻隔基材迅速升温方面具有明显效果。试验合成了聚苯胺-碳化硅(PANI-SiC)复合材料,通过SEM、FTIR、XRD等手段分析了复合材料的形貌、组成和结构,考察了单组分膨胀型防火涂料乳液的种类及复合材料含量对涂层防火耐火性能的影响。结果表明:醋酸乙烯-乙烯(VAE)乳液相比于苯丙乳液和丙烯酸乳液可以更好地提升涂层的膨胀倍率和耐火性能。随着PANI-SiC含量的增加,涂层的膨胀倍率增加,背面温度降低,10%含量复合材料的防火涂层表现出优异的耐火性能。

壳聚糖基膨胀阻燃涤纶/棉混纺织物的制备及其性能

为得到阻燃且满足实际应用需求的涤纶/棉混纺织物(T/C),选用亚磷酸化壳聚糖(PCS)和γ-哌嗪基丙基甲基二甲氧基硅烷(GP-108)制备阻燃整理剂(PCS/GP),通过一步浸渍法对涤纶/棉混纺织物进行整理,并研究其微观表面形貌、热稳定性能、阻燃性能、拉伸性能以及白度等。结果表明:PCS/GP成功在涤纶/棉混纺织物表面沉积成膜,包裹住涤纶/棉纤维;T/C-PCS/GP呈现典型的涤纶/棉混纺织物二步热降解过程,在700℃时保留有28.5%的残炭量,说明PCS/GP提高了阻燃涤纶/棉混纺织物在高温区的热稳定性能;T/C-PCS/GP的LOI值提升至26.5%,实现了垂直燃烧测试中的离火自熄,残炭扫描电镜照片表明,PCS/GP的沉积改善了涤纶/棉混纺织物燃烧时存在的“支架”效应;T/C-PCS/GP的热释放速率峰值和火灾蔓延指数较T/C分别降低了20%和40%,表明其火灾危险性大幅度降低;锥形量热测试后的残炭电镜照片表明,T/C-PCS/GP能够保留完整的织物编织结构,残炭表面存在明显的膨胀炭层,与垂直燃烧测试结果相符;热重红外测试结果表明,T/C-PCS/GP分解提前,主要影响棉组分热降解并促进其成炭,而高温区的红外谱图表明,在致密炭层的保护下,T/C-PCS/GP的热降解得到抑制。T/C-PCS/GP与T/C-PCS相比,断裂强力提升17%,其断裂强力与T/C的断裂强力相差不大;同时,GP-108的使用改善了T/C-PCS的黄变问题,提升了T/C-PCS/GP的白度。然而,阻燃样品耐久性较差,需要后续改进。

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。

IFR/OMMT协同阻燃长玻纤增强聚丙烯的阻燃性能和热稳定性能研究

以膨胀阻燃剂(IFR)和有机蒙脱土(OMMT)协效阻燃剂对长玻纤增强聚丙烯复合材料(LGFPP)进行阻燃改性,研究OMMT与IFR阻燃剂的协同效应对LGFPP阻燃性能和热稳定性能的影响。采用氧指数(LOI)和热失重分析(TGA)表征LGFPP的阻燃性能和热稳定性能,并通过扫描电镜(SEM)观察燃烧后的炭层形貌。结果表明,OMMT的加入提高了LGFPP/IFR体系的阻燃性能和热稳定性能;当OMMT添加量为2%时,体系的氧指数达到24.2%,燃烧后的残炭物形成致密的硅酸盐保护层。

双氯螺磷及膨胀型阻燃剂(IFR)的合成研究

以三氯氧磷 (POCl3)、季戊四醇 (PEL)和三聚氰胺 (MEL)为原料 ,研究反应温度、时间及原料加入方式等工艺条件对转化率及产品双氯螺磷收率的影响 ,探讨IFR合成的最佳工艺条件 ,所得结果将为IFR的工业化生产提供理论依据。