磷杂菲类阻燃剂的合成及其与聚磷酸铵复合膨胀体系对环氧树脂的阻燃性能研究

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、五硫化二磷(P2S5)为原料合成9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS),并将DOPS与聚磷酸铵(APP)组成复合阻燃剂,用于环氧树脂(EP)的阻燃改性.通过氧指数(LOI)、垂直燃烧(UL-94)、热失重(TGA)、锥形量热(CONE)和扫描电镜(SEM)等方法对改性后的环氧树脂的阻燃性能和阻燃机理进行了测试和分析.实验结果表明,DOPS/APP阻燃体系对EP具有很好的阻燃性能,且复配阻燃剂的阻燃效果比单一的阻燃剂阻燃效果好;其中,当阻燃剂的总添加量达到30%时即W_(DOPS)=10%、W_(APP)=20%时,阻燃EP复合材料的LOI值可达到29.2%,垂直燃烧等级达到UL-94 V-0级,残炭量可达49.3%.     

OMMT-NC-膨胀型阻燃剂三元协同阻燃LLDPE的效果

采用有机蒙脱土(OMMT)和碳酸镍(NC)为阻燃协效剂,与膨胀型阻燃剂(IFR)三元体系协同阻燃线性低密度聚乙烯(LLDPE).采用热重分析(TGA)、氧指数(LOI)测试、UL-94燃烧测试和锥形量热测试(CONE)研究了LLDPE阻燃体系的热稳定性和燃烧性能;采用红外光谱分析(FT-IR)、数码相机和扫描电子显微镜(SEM)对燃烧残余物的结构和形貌进行了分析.结果表明:固定mnLLDPE/mIFR=7/3,当moMMT/m(LLDPE+IFR)=0.04时,阻燃体系的LOI为31.5％,通过UL-94 V-0级测试,LLDPE-IFR-OMMT的残炭率为15.09％,最大热释放速率(PHRR)相比于纯LLDPE降低了50％;向LLDPE-IFR-OMMT体系中添加NC,少量的NC就能显著增加体系的阻燃性能,当mNC/m(LLDPE+IFR)=0.02时,阻燃体系的LOI为32.7％,LLDPE-IFR-OMMT-NC的残炭率达到19.04％,PHRR相比于纯LLDPE降低了57％.OMMT和NC的加入能催化LLDPE-IFR成炭,形成致密的炭层,增加炭层的强度,从而提高复合材料的阻燃性能.     

协效阻燃聚丙烯的阻燃性能

本文研究了以聚磷酸铵(APP)为主阻燃剂,次磷酸铝(AHP)和三聚氰胺氰尿酸盐(MCA)为辅阻燃剂的协效阻燃体系对聚丙烯(PP)阻燃性能的影响。 采用垂直燃烧测试、极限氧指数(LOI)测试、热重分析、锥形量热仪测试、扫描电子显微镜分析等技术手段对所制备的阻燃样品进行了阻燃性能分析。 结果表明:单独添加任一质量分数30%阻燃剂,均不能使PP获得良好的阻燃性能;当阻燃剂总质量分数保持在30%,m(APP)：m(AHP)：m(MCA)=4：1：1时获得理想阻燃效果,此时阻燃PP的LOI为33%,垂直燃烧测试达到V-0级,热释放速率峰值(PHRR)从765.7 kW/m²降为122.7 kW/m²。     

聚磷酸铵的疏水改性及聚丙烯阻燃性能

首先以γ-氨丙基三乙氧基硅烷(KH550)对聚磷酸铵(APP)进行表面化学修饰,然后用水解后的正硅酸四乙酯在其表面引发原位聚合,最后用十七氟癸基三乙氧基硅烷(氟硅烷)进行外表面修饰,制备了疏水聚磷酸铵(M-APP).M-APP的静态接触角为134°,表明M-APP具有很好的疏水性.通过傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)对M-APP的结构及表面元素进行分析,结果表明,M-APP即为目标产物.将M-APP与三嗪成炭发泡剂(CFA)以质量比4∶1复配制备改性膨胀型阻燃剂(M-APP/CFA),并添加到聚丙烯(PP)中,制备阻燃PP(PP/M-APP/CFA).通过极限氧指数(LOI)和垂直燃烧(UL-94)研究了其阻燃性能,用热重分析(TGA)研究了材料的热降解行为,通过耐水测试研究了耐水性能,通过拉伸、弯曲和冲击强度研究了材料的力学性能,通过扫描电子显微镜(SEM)研究了改性膨胀型阻燃剂与聚合物的相容性.结果表明,当m IFR的添加量为23%时,PP/M-APP/CFA通过UL-94 V-0级,LOI值达到30.8%,且经过耐水测试后,依然能通过UL-94 V-0级,PP/M-APP/CFA的失重率仅为0.92%.在相同实验条件下,由APP制备的PP/M-APP/CFA材料在耐水测试后UL-94测试无级别,失重率达2.45%,表明APP的表面疏水改性大大提高了PP/M-APP/CFA材料的耐水性能.M-APP/CFA的加入提高了材料的热稳定性及成炭性能,燃烧时形成的膨胀炭层能很好地保护内部材料的降解和燃烧,从而提高了材料的阻燃性能.APP的改性提高了M-APP/CFA与PP的相容性,从而提高了材料的力学性能.     

三聚氰胺氰尿酸盐对玻纤增强尼龙66复合材料阻燃性能的影响

将三聚氰胺氰尿酸盐(MCA)阻燃剂添加到玻纤增强的尼龙66复合材料(GF-PA66)中。利用UL-94实验对MCA在复合材料中的阻燃效果进行研究;通过扫描电子显微镜(SEM)分析了燃烧后的样品形貌,并利用热重分析法对复合材料的热分解行为进行了研究。结果表明:MCA可使玻纤增强尼龙66复合材料达到UL-94V-0级阻燃效果;MCA晶体被均匀地分散于尼龙基体中,在燃烧时MCA通过自身吸热分解,产生不可燃气体,实现气相阻隔,从而起到阻燃作用,并在复合材料自熄面上留下纳米级气孔。     

新型含磷阻燃剂DOPO-PPO的合成及其阻燃性能

以苯基磷酰二氯,对羟基苯甲醛及9,10-二氢-9-氧杂-10-磷杂菲(DOPO)为原料,合成了一种新型含磷阻燃剂——二[4-(次甲基-羟基-磷杂菲)苯氧基]苯基氧化磷(DOPO-PPO),其结构经1H NMR和IR表征。通过TGA和DTG研究了DOPO-PPO的热稳定性,热降解行为及成炭性能。结果表明:DOPO-PPO的起始热分解温度为210℃,在700℃时残炭为30.4%。以环氧树脂为基材,DOPO-PPO为阻燃剂,二氨基二苯硫砜为固化剂,制备了阻燃环氧树脂(3)。通过极限氧指数(LOI)和垂直燃烧(UL-94)测试了3的阻燃性能。结果表明:当DOPOPPO的添加量为12.0%(质量百分数,即312)时,阻燃级别为V-0级,LOI为34.0%。     

阻燃PA66/二乙基次磷酸铝复合材料的研究

通过双螺杆挤出机熔融共混制备了阻燃PA66/二乙基次磷酸铝(ADP)复合材料,采用极限氧指数(LOI)、垂直燃烧(UL94)测试、锥形量热仪(Cone)等研究了PA66/ADP材料的燃烧性能,同时还通过拉伸、弯曲强度测试考察了PA66/ADP复合材料的力学性能.研究表明:ADP添加量为8%时,该体系达到了UL94V-0级,LOI值由25. 3%提高到30. 2%. PA66/ADP材料的热释放速率峰值由1 168 k W/m2下降到535 k W/m2,添加ADP能够显著地增强成炭率,增强隔热作用.     

PP/EVA/OMMT纳米复合材料及其阻燃材料的动态燃烧行为

利用锥形量热仪(CONE)在35kW/m2热辐照条件下,并结合极限氧指数(LOI)和UL-94垂直燃烧测试方法对聚丙烯(PP)/乙烯-醋酸乙烯酯共聚物(EVA)/有机蒙脱土(OMMT)纳米复合材料和加入无卤复配阻燃剂制备的PP/EVA/OMMT/氢氧化铝(ATH)/三氧化二锑(AO)纳米复合阻燃材料的热释放速率、烟释放及材料在燃烧时的质量损失行为进行了研究。结果表明,添加5%(质量分数)OMMT可以提高PP/EVA复合材料的阻燃性能,燃烧时的热释放速率、质量损失率以及烟释放量减少,且OMMT与无卤复配阻燃剂之间可产生阻燃协同作用,使纳米复合阻燃材料的阻燃性能、热稳定性和抑烟性进一步增强。     

不同囊材聚磷酸铵微胶囊在环氧树脂中的阻燃研究

采用原位聚合法合成制备了以蜜胺树脂(MF)、环氧树脂(EP)以及EP和MF为囊材的微胶囊阻燃剂MFAPP、EPAPP、EMFAPP,用红外光谱(FT-IR)和扫描电镜(SEM)表征微胶囊阻燃剂的核壳结构。采用极限氧指数(LOI)和垂直燃烧等级测试(UL94)对MFAPP、EPAPP、EMFAPP在环氧树脂中的阻燃特性进行了研究。当添加量大于7%时,阻燃复合材料均能通过UL 94 V-0级测试,极限氧指数大于27.0%,表明MFAPP、EPAPP、EMFAPP均为EP的高效阻燃剂,这些阻燃剂在EP阻燃过程中均形成了膨胀炭层,属于膨胀阻燃机理。另外在耐水性实验中发现,添加EPAPP、EMFAPP的EP复合材料具有更好的耐水性,经75℃水浸泡6天后,阻燃性能得到了较好的保持。     

膨胀型类磷酸酯蜜胺盐阻燃剂的合成及应用研究

以双季戊四醇(DPE)、五氧化二磷、水和三聚氰胺为原料,合成了膨胀型环状类磷酸酯蜜胺盐阻燃剂。通过实验提出了合成该阻燃剂的最佳反应条件为：双季戊四醇(DPE)、五氧化二磷、水和三聚氰胺反应物料摩尔配比为1／2．5／2.0／3．45、反应时间4h和反应温度120℃。红外吸收图谱分析表明该阻燃剂具有环状结构,在热重分析和差热分析中该阻燃剂显示出优异的热稳定性和很高的成碳性。以该阻燃剂掺入聚丙烯中,阻燃效果显著,经测试阻燃聚丙烯的极限氧指数(LOI)为33．6,烟密度等级(SDR)为44．25,通过了UL94V-0级。     

聚磷酸酯阻燃剂复配聚磷酸铵对环氧树脂阻燃性能的影响

合成了一种9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)的衍生物——聚苯氧基磷酸-2-10-氢-9-氧杂-磷杂菲基对苯二酚酯(POPP), 以间苯二胺(m-PDA)为固化剂, 环氧树脂(EP)为基料, POPP为阻燃剂, 复配聚磷酸铵(APP), 制备了不同磷含量的阻燃环氧树脂. 利用极限氧指数(LOI)和垂直燃烧(UL94)实验表征了环氧树脂的阻燃性能; 以热重分析、 锥型量热和扫描电镜分析了阻燃环氧树脂的热性能和表面形态. 研究结果表明, 阻燃剂总加入量(质量分数)为5%时即可达到UL94 V-0级, 同时LOI值为27.7%; 当总加入量为15%, 即w_POPP=5%, w_APP=10 %时, 其LOI值可达到33.8%. 随着磷含量的增加, 阻燃环氧树脂的初始降解温度略有降低, 但高温下的残炭率明显增加. POPP/APP的加入在很大程度上降低了环氧树脂的热释放速率、 有效燃烧热、 烟释放量和有毒气体释放量. 阻燃环氧树脂在高温下形成比较稳定的致密膨胀炭层, 为底层的环氧树脂主体隔绝了分解产物及热量和氧气交换, 增强了高温下的热稳定性.     

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.     

一种无卤阻燃ABS体系的阻燃性能研究

ABS是本世纪40年代发展起来的通用型热塑性材料[1],它有良好的力学性能,耐化学腐蚀、易加工等优点[2-6].     

Thermogravimetry as a tool for measuring of fracturing fluid absorption in shales

A series of flame-retardant ethylene–vinyl acetate (EVA) composites with different contents of aluminum phosphate (AHP) and Trimer were prepared. The synergistic flame-retardant effects of the Trimer with AHP in EVA/AHP blends were studied by limiting oxygen index (LOI) tests, UL-94 tests, cone calorimeter tests, thermogravimetric analysis, and scanning electron microscopy (SEM). The LOI and UL-94 results showed that the system containing AHP and Trimer was very effective in improving the flame retardancy of EVA. When the mass ratio of AHP and Trimer was 3:1, the highest flame retardancy could be obtained, and when the flame-retardant loading was 30 wt%, the EVA/AHP/Trimer (7.5%) sample could achieve the V-0 rating in UL-94 tests, at the same time, its LOI value was 24.4%. The TG and DTG results showed that the addition of flame retardants catalyzes EVA decomposition in the first stage and generates a more stable char residue in the second stage. Consequently, an efficient reduction in the flammability parameters, such as heat release rate, total heat release, smoke production rate, and total smoke production could be observed. In addition, it was observed from the SEM observations of the morphological features that the AHP and Trimer combination, at the optimum proportion, could promote the formation of compact charred layers and prevent their cracking, which effectively protected the underlying materials from burning.     

Simultaneous improvement in the flame retardancy and water resistance of PP/APP through coating UV-curable pentaerythritol triacrylate onto APP

To improve the flame-retardant efficiency and water resistance of ammonium polyphosphate(APP), the UV-curable pentaerythritol triacrylate(PETA) was used to microencapsulate APP via the UV curing polymerization method. The prepared PETA-microencapsulated APP(PETA-APP) was characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), and thermogravimetric(TG) analysis. PETA-APP was used as intumescent flame retardant(IFR) alone to flame retard polypropylene(PP). The water resistance of PP/PETA-APP composites was investigated, and the effect of PETA on the combustion behaviors of PP/APP composites was studied through limiting oxygen index(LOI), vertical burning test(UL-94) and cone calorimeter(CC) test, respectively. With 40 wt% of PETA-APP, the PP/PETA-APP system could achieve a LOI value of 30.0% and UL-94 V-0 rating after treatment in hot water for 168 h, while the LOI value of the system containing 40 wt% uncoated APP was only 19.2%, and it failed to pass the UL-94 rating. CC test results showed that the heat release rate(HRR), mass loss rate(MLR) and smoke production rate(SPR) of PP/PETAAPP system decreased significantly compared with PP/APP system, especially the peak of HRR was decreased by 51.4%. The mechanism for the improvement of flame reatardancy for PP/PETA-APP composites was discussed based on FTIR and X-ray photoelectron spectroscopy(XPS) tests. All these results illustrated that simultaneous improvement of flame retardancy and water resistance for PP/APP was achieved through coating UV-curable PETA onto APP.     

Combustion properties and thermal degradation behavior of polylactide with an effective intumescent flame retardant

An intumescent flame retardant spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine (SPDPM) has been synthesized and its structure was characterized by Fourier transformed infrared spectrometry (FTIR), ¹H and ³¹P nuclear magnetic resonances (NMR). A series of polylactide (PLA)-based flame retardant composites containing SPDPM were prepared by melt blending method. The combustion properties of PLA/SPDPM composites were evaluated through UL-94, limiting oxygen index (LOI) tests and microscale combustion calorimetry (MCC) experiments. It is found that SPDPM integrating acid, char and gas sources significantly improved the flame retardancy and anti-dripping performance of PLA. When 25 wt% flame retardant was added, the composites achieved UL-94 V0, and the LOI value was increased to 38. Thermogravimetric analysis (TGA) showed that the weight loss rate of PLA was decreased by introduction of SPDPM. In addition, the thermal degradation process and possible flame retardant mechanism of PLA composites with SPDPM were analyzed by in situ FTIR.     

Thermal stability of food additives of glutamate and benzoate type

Summary An unsaturated polyester/sisal flame retardant composite was formulated using decabromine diphenyl oxide associated with antimony trioxide as additives. The development and use of natural or vegetable fiber reinforced composites is increasing worldwide, since natural fibers come from renewable sources and their use contributes to the so-called 'green technology'. In the present study, the synergic effect of a bromine/antimony (3:1 molar ratio) based flame retardant system with 7.5% Br (mass/mass) added to composites investigated by TG, UL-94V and pyrolysis on a coupled Pyr-GC/MS device. The efficiency of the flame retardant system is confirmed by TG and UL-94V test where the composite containig flame retardant system obtained the highest classification (V-0).     

Flame retardation of glass-fibre-reinforced polyamide 6 by a novel metal salt of alkylphosphinic acid

Aluminum salts of phosphinic acid mixture of diisobutylphosphinic acid and monoisobutylphosphinic acid (HPA-2TBA-Al) and glass fibres were compounded with polyamide 6 to prepare a series of flame retardant GF/PA6 composites via melt blending. The flame retardance and burning behaviors of the composites were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), and Cone calorimeter test. The thermal properties and decomposition kinetics were investigated by thermogravimetric analysis (TGA) under N₂ atmosphere. Addition of HPA-2TBA-Al results in an increased LOI value, a UL-94 V-0 rating together with a decrease in both the values of PHRR and THR in Cone calorimetric analysis. Visual observations and scanning electronic microscopy (SEM) after flame retardant tests confirmed the char-formation which acts as a fire barrier in condense phase. Analysis of cone calorimeter data indicates that gas phase flame retardant mechanism exists in the GFPA6/HPA-2TBA-Al system.     

The investigation of intumescent flame-retarded ABS using zinc borate as synergist

The influence of zinc borate (ZB) on the flammability and thermal properties of acrylonitrile–butadiene–styrene copolymer (ABS)/ammonium polyphosphate (APP)/poly(p-ethylene terephthalamide) (PETA) system was investigated. When the loadings of ABS, APP, PETA, and ZB were 70, 20.8, 6.9, and 2.3 %, respectively, the LOI value reached 36 and UL-94 vertical burning test was V-0. Even when 1.5 % ZB was added into ABS/APP/PETA (80/13.9/4.6) system, the LOI value was also 27. The thermal degradation of the composites was investigated by means of thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). The TG indicated that the addition of ZB improved the thermal stability and the char residue of the ABS/APP/PETA system. What’s more, the mechanism was investigated by FTIR. The spectrum of flame retardant residue suggested that ZB reacted with APP/PETA physically. Additionally, scanning electron microscopy showed that the surface of intumescent charred layer obtained after combustion of ABS/APP/PETA/ZB (70/20.8/6.9/2.3) was compact and thick.