磷钨酸在膨胀阻燃聚乳酸中的协效作用研究

利用磷钨酸(PWA)与膨胀阻燃剂(IFR)复配得到复合阻燃剂,并与聚乳酸(PLA)熔融共混制备阻燃复合材料PLA/IFR/PWA。通过氧指数测试(LOI)、垂直燃烧(UL-94)、扫描电子显微镜(SEM)、锥形量热测试(CONE)和热失重分析(TGA)对该复合材料的阻燃性能和热稳定性能进行研究。结果表明:PLA/IFR/PWA复合材料表现出优异的阻燃效果和明显的抑烟作用。当添加总质量分数为20%(IFR为18%,PWA为2%)时,复合材料的LOI达到41.7%,UL-94等级为V-0等级,高温残炭量显著提高,燃烧过程中烟释放量明显降低。     

PBT/TPU/DOPO-MA阻燃复合材料的制备及性能

通过使用9,10-二氢-9-氧杂-10-磷朵菲-10-氧化物（DOPO）和马来酸酐反应合成制备DOPO衍生物阻燃剂DOPO-MA，并且其结构使用傅里叶红外光谱分析（FTIR）和核磁共振氢谱分析（¹H NMR）技术进行表征。将阻燃剂与聚对苯二甲酸丁二醇酯（PBT）和热塑性聚氨酯（TPU）熔融共混以制备PBT/TPU/DOPO-MA阻燃复合材料。通过运用锥形量热、UL-94、极限氧指数（LOI）、热重分析（TGA）、差热分析（DSC）和力学测试，研究了阻燃剂对复合材料的性能影响。测试结果表明，PBT/TPU/DOPO-MA复合材料具有良好的阻燃性能，加入10％DOPO-MA后，LOI从23.2增加到31.6，可达到UL-94 V-1等级，热释放率峰值（PHRR）和最大成热辐射速率（MAHRE）值降低；热重分析测试结果表明，添加DOPO-MA可以使得阻燃复合材料的热稳定性有显著的提高，当加入10％DOPO-MA后，残炭量可从6.87增加到14.36。此外，随着DOPO-MA含量的增加，阻燃复合材料的结晶度可得到一定的提高。     

改性赤泥协同膨胀型阻燃剂阻燃聚乙烯

以聚磷酸铵（APP）、季戊四醇（PER）和三聚氰胺（MEL）复配的膨胀型阻燃体系（IFR）为主要阻燃剂,表面改性后的赤泥（Ti-MRM）作为协效剂阻燃聚乙烯（PE）,采用熔融共混法制备PE基阻燃复合材料（PE/IFR-Ti-MRM）。通过热重分析仪（TGA）、垂直燃烧仪（UL-94）、极限氧指数测定仪（LOI）及扫描电镜（SEM）等对其热氧稳定性、燃烧等级、阻燃性能和残炭形貌进行了表征与分析。结果表明：加入改性赤泥的PE/IFR-Ti-MRM复合材料形成的炭层更加致密和连续,当最优配比时,复合材料的极限氧指数达到32.2,燃烧等级达到V-0级;而PE/IFR阻燃复合材料的极限氧指数只能达到27.5,燃烧等级为V-2级。     

聚磷酸酯膨胀阻燃剂复配有机蒙脱土阻燃改性环氧树脂

以间苯二胺为固化剂,聚苯氧基磷酸210氢9氧杂磷杂菲对苯二酚酯（POPP）、聚磷酸铵（APP）为阻燃剂, 复配质量分数为1 %有机蒙脱土（OMMT）为膨胀阻燃体系,对环氧树脂（EP）进行阻燃改性。通过极限氧指数测定仪、垂直燃烧测定仪同步热分析仪、锥形量热等研究改性EP的阻燃性能、热性能和力学性能。结果表明,当膨胀阻燃体系（2.5 %POPP/APP+1 %OMMT）添加量为3.5 %时,改性EP可达UL 94 V-0级,同时LOI为25.2 %;当膨胀阻燃体系添加量为11 %时,改性EP的LOI值进一步升高到31.7 %;阻燃剂的加入,使EP的初始分解温度略有降低,但残炭量明显增加;POPP/APP/OMMT的加入很大程度上降低了EP的热释放速率、烟释放量和平均热释放速率。     

无卤膨胀阻燃长玻纤增强聚丙烯性能研究*

利用无卤膨胀阻燃剂(IFR)阻燃长玻纤增强聚丙烯(LGFPP)复合材料,研究IFR的添加量对复合材料阻燃性能、热稳定性能、燃烧性能和力学性能的影响。结果表明,加入IFR使复合材料燃烧后生成了具有阻燃作用的炭层,显著提高了复合材料的阻燃性能。随IFR添加量的增加,复合材料的极限氧指数(LOI)逐渐提高,热释放速率峰值及其平均值、总热释放速率和生烟速率逐渐降低,力学性能略有下降。当IFR质量分数为20%时,复合材料的LOI和垂直燃烧等级分别达到了24.4%和UL 94 V-0级。     

卡拉胶/金属氧化物协同聚磷酸铵制备阻燃天然橡胶

将卡拉胶（KC）、聚磷酸铵（APP）分别和Fe2O3、CuO、Al2O3、MnO2 4种金属氧化物（MO）三者复配构成的协同阻燃剂（KC/MO/APP）加入到天然橡胶（NR）中，制备NR/KC/MO/APP复合材料。通过极限氧指数（LOI）、垂直燃烧（UL-94）、锥形量热（CCT）测试了复合材料阻燃性能。结果表明，NR/KC/MO/APP复合材料的UL-94均达到V-0等级，LOI在26.5%~27.3%之间，具有较好的阻燃性。与NR相比，NR/KC/CuO/APP复合材料的热释放速率峰值（pHRR）和总热释放量（THR）分别下降了63.7%和42.0%。同时KC/MO/APP还有抑烟作用，NR/KC/Fe2O3/APP复合材料总烟释放量（TSP）比NR下降了35%，处于最低水平。TGA结果显示，NR/KC/CuO/APP复合材料W800达到34.85%，比NR/APP提高了28.7%。SEM分析表明，NR/KC/MO/APP复合材料体系炭层更致密，表明KC/MO与APP的协同作用对形成稳定炭层起着重要作用。DMA和力学性能测试发现，NR/KC/MnO2/APP复合材料力学性能最优，其拉伸强度和断裂伸长率比NR/APP分别提高32.6%和20.9%，表明MnO2的加入可弥补阻燃剂对NR造成的力学性能损失。     

氨基磺酸胍对尼龙6阻燃性能的影响

以氨基磺酸胍(GAS)为阻燃剂制备了无卤阻燃尼龙6(PA6)复合材料。通过极限氧指数(LOI)和垂直燃烧(UL-94)以及热失重分析仪(TGA)研究了GAS对尼龙6阻燃性能与热稳定性的影响,通过TGA-FTIR联用分析复合材料热氧化分解释放的气体产物。结果表明:加入9%的GAS后,材料的氧指数提高到31.9%,垂直燃烧达到V-0等级,GAS能同时在气相和固相中起到阻燃作用,在气相中释放不可燃性气体,在固相中促进残炭的生成。     

含磷阻燃剂对环氧树脂胶粘剂阻燃性能的影响

以双酚A二缩水甘油醚为单体,4,4'-二氨基二苯甲烷为固化剂,六苯氧基环三磷腈(HPCTP)和有机改性的二氧化硅为填料,通过原位聚合的方法,制备阻燃型环氧树脂复合材料。采用热重分析法研究阻燃剂对复合材料热降解性能的影响,结果表明,加入含磷阻燃剂后,复合材料的热稳定性有所降低;采用极限氧指数(LOI)、UL-94垂直燃烧和锥形量热法研究复合材料的阻燃性能,加入HPCTP后,复合材料达到V-0级别,锥形量热的各种参数都得到改善。     

有机次膦酸盐复配型阻燃剂阻燃LGFPA6的制备

采用新型有机次膦酸盐复配型阻燃剂制备无卤阻燃长玻纤增强尼龙6(LGFPA6)复合材料。通过垂直燃烧(UL94)、极限氧指数(LOI)、热重(TG)分析、差示扫描量热(DSC)仪及力学性能测试系统研究了阻燃剂含量对LGFPA6复合材料性能的影响。结果表明,阻燃剂质量分数为15%时,可使阻燃LGFPA6复合材料的阻燃等级达到UL94 V–0级,LOI为28.0%,力学性能最佳。TG分析表明,阻燃剂降低了LGFPA6的热稳定性,促进基体成炭。DSC结果表明,阻燃剂质量分数为15%时,对LGFPA6的结晶性能影响最小。阻燃剂质量分数为15%时,复合材料的综合性能最好。     

聚乳酸/苯基次膦酸铈复合材料的制备及性能

采用简单方法合成苯基次膦酸铈(CeP),并将其作为阻燃剂加入聚乳酸(PLA)中,通过熔融共混技术制备聚乳酸/苯基次膦酸铈(PLA/CeP)复合材料。通过热重(TG)、极限氧指数(LOI)、UL-94垂直燃烧(UL-94)、微型量热(MCC)研究复合材料的热稳定性、阻燃性能和燃烧性能。通过阻燃测试发现,CeP能够提高复合材料阻燃性能,PLA/CeP20极限氧指数能达到24.3%并通过UL-94 V-2级别。热重分析的结果表明,CeP显著提高了PLA/CeP复合材料初始分解温度和成炭率。MCC测试结果表明,CeP能明显降低PLA/CeP复合材料火灾危险性。PLA/CeP20热释放速率峰值(PHRR)和总热释放(THR)分别为397 W/g和13.6 kJ/g,与纯聚乳酸相比,分别下降了13.9%和28.0%。因此,苯基次磷酸铈对聚乳酸具有良好的阻燃效果。     

Effect of phosphorus–nitrogen compound on flame retardancy and mechanical properties of polylactic acid

A phosphorus-nitrogen flame retardant (PN) was synthesized by using cytosine and diphenylphosphinic chloride. The flame retardancy and thermal stability of polylactic acid (PLA)/PN composites were investigated by the UL-94 vertical burning test, limited oxygen index (LOI), cone calorimeter test, and thermogravimetric analysis. The PN performs efficiently on improving the flame retardancy of PLA. The PLA composite achieves the UL-94 V-0 rating and its LOI increases to 30.4 vol% by adding 0.5 wt% PN. The flame retardant mechanism analysis showed that PN catalyzes the degradation of PLA to improve the flame retardancy by melting-away mode. Meanwhile PN reduces the release of flammable gasses during thermal degradation of PLA by promoting the transesterification of PLA, which is helpful for extinguishing flame. Moreover, triglycidyl isocyanurate (TGIC) was used as a micro-crosslinking agent to reduce the loss of mechanical properties of PLA/PN composites caused by degradation. Adding 0.1 wt% TGIC and 1.0 wt% PN into PLA, the tensile strength and elongation at break of PLA/PN are increased to the same level as that of PLA. Therefore, PLA with excellent comprehensive performance can be obtained.     

Combustion Behavior and Thermal Oxidative Degradation of EVA Containing Intumescent Flame Retardant

Microencapsulated ammonium polyphosphate (VAPP) with poly(vinyl alcohol)- melamine-formaldehyde (VMF) shell was introduced in ethylene vinyl acetate copolymer (EVA) to improve its flame retardancy. Due to the presence of VMF shell, VAPP shows better compatibility, flame retardancy and water resistance compared with ammonium polyphosphate (APP) in EVA. The flammability of EVA and its flame-retarded composites was studied by LOI, UL-94 and cone calorimeter. The composite containing 40 wt% VAPP can pass V-0 in UL-94 test, and hot water treatment shows few effects on its LOI value and UL-94 rating. The cone results indicated that the use of VAPP in EVA can significantly decrease heat release rate and total heat release compared with APP. To understand the mechanism of action of VAPP, dynamic FTIR experiments were carried out on EVA and EVA/VAPP composites. Based on above studies, the flame retardant mechanism of VAPP in EVA composite is discussed.     

Synthesis of a novel intumescent flame retardant and its flame retardancy in polypropylene

Microencapsulated ammonium polyphosphate (GMFAPP) is prepared by in situ polymerization method with a shell of poly(ethylene glycol) modified melamine-formaldehyde resin. Due to the presence of shell, GMFAPP shows less size, higher water resistance and flame retardancy in polypropylene (PP) compared with ammonium polyphosphate (APP). The flame retardant action of GMFAPP and APP in PP are studied using LOI, UL-94 and cone calorimeter, and their thermal stability is evaluated by thermogravimetric apparatus. The limiting oxygen index (LOI) value of the PP/GMFAPP at the same loading is higher than the value of PP/APP. UL-94 ratings of PP/GMFAPP can reach V-0 at 30 wt% loading. The water resistant properties of the PP composites are studied, and the results of the composites containing with APP and GMFAPP are compared. The cone results put forward that GMFAPP is an effective flame retardant in PP compared with APP. Moreover, the thermal oxidative behavior of GMFAPP is evaluated by dynamic FTIR to study its flame retardant mechanism in PP.     

卡拉胶-纳米氢氧化铝协同阻燃天然橡胶

将BaCl2分级的k型卡拉胶(KC)和纳米氢氧化铝〔Al(OH)3〕构成的协同阻燃体系添加到天然橡胶(NR)中制备KC-Al(OH)3/NR复合材料。通过TG、极限氧指数(LOI)、锥形量热(CCT)以及SEM考察了不同质量比的KC和Al(OH)3对复合材料力学性能和阻燃性能的影响。结果表明,当KC与Al(OH)3以1∶1的质量比加入到NR时,KC-Al(OH)3/NR复合材料的热稳定性、阻燃性能最优,复合材料的LOI达到25%。与纯天然橡胶相比,复合材料总热释放量(THR)、热释放速率峰值(pHRR)、总烟释放量(TSP)和平均质量损失率(AMLR)分别降低了12%、65%、23%和62%。相比于单独添加Al(OH)3体系,复合材料拉伸强度和断裂伸长率分别增加了11%和17%。     

Synergistic effects of aluminium hypophosphite on the flame retardancy and thermal degradation behaviours of a novel intumescent flame retardant thermoplastic vulcanisate composite

ABSTRACT

The synergistic effects of aluminum hypophosphite (AHP) on the flame retardancy, thermal degradation behaviors of a novel intumescent flame retardant thermoplastic vulcanizate (TPV/IFR) composite were investigated. The results showed that the combination of AHP with IFR showed evident synergistic effects on the increase in the LOI value and reduction of the combustion parameters for the TPV/IFR/AHP composites at the optimum weight ratio of IFR/AHP (6/1) as evidenced by LOI, UL-94 and CCT. The TGA data revealed that AHP could change the degradation behavior of TPV/IFR composites and enhance the thermal stability of the TPV/IFR composites at high temperature. The results of FTIR, EDXS, LRS and SEM demonstrated that TPV/IFR/AHP composites could form more continuous, dense and stable char layer on the materials surface, and consequently improving the flame retardancy. Based on these results, the possible condensed flame retardant mechanism of TPV/IFR/AHP composites was concluded in detail.     

Effect of talc on thermal stability and flame retardancy of polycarbonate/PSBPBP composite

A novel flame retardant poly(3-aminopropyl methylsiloxane bis(3-hydroxy phenyl spirocyclic pentaerythritol bisphosphate)) (PSBPBP) in combination with talc was blended into polycarbonate (PC) by melt compounding. The flame retardancy and thermal stability of PC/PSBPBP/talc composites were investigated by limiting oxygen index (LOI) test, UL-94 rating test, thermogravimetric analysis (TGA), Raman spectroscopy (RS), and scanning electron microscope (SEM). The mechanical properties were also measured in this work. Increasing talc content leads to observed improvement on flame retardancy of PC composites. LOI value of PC/PSBPBP/10 wt % talc system was 34, and this system passed V0 rating in the UL-94 test. The char yield at 700°C was 28.2% and the onset decomposition temperature shifted up to 540°C for PC/10% PSBPBP/10% talc system in TGA. In the Raman measure, the R value and G linewidth of PC/PSBPBP with 10 wt % talc composite increased to 1.41 and 65 cm⁻¹ from 1.12 and 43 cm⁻¹ of pure PC, respectively. The Raman results suggest that the char residue of PC/PSBPBP with talc composites was denser and had better barrier property, which is agreement with the SEM results. Besides, talc had no remarkable influence on the mechanical properties of PC/PSBPBP composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Vinyl polysiloxane microencapsulated ammonium polyphosphate and its application in flame retardant polypropylene

Vinyl polysiloxane microencapsulated ammonium polyphosphate (MAPP) was prepared by a sol-gel method using vinyltrimethoxysilane as a precursor to improve its thermal stability and hydrophobicity. The MAPP was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and thermogravimetric analyzer (TGA). The results showed that ammonium polyphosphate (APP) was successfully coated with vinyl polysiloxane. MAPP and pentaerythritol (PER) were used together to improve the flame retardancy of polypropylene (PP). The flame retardant properties of PP composites were investigated by limiting oxygen index (LOI), UL-94 test, TGA and SEM. When the MAPP was added as a flame retardant, with PER as a char forming agent, the LOI of PP/MAPP/PER composites was 33.1%, and it reached the UL-94 V-0 level. The results also demonstrated that the flame retardant properties of PP/MAPP/PER composites were better than those of PP/APP/PER composites at the same loading. Moreover, the addition of flame retardant and carbon forming agent could promote the crystallization behavior of PP.     

A monomolecular organophosphate for enhancing the flame retardancy,thermostability and crystallization properties of polylactic acid

Polylactic acid (PLA) is regarded as one of the most promising bioplastics. However, its inherent high flammability of PLA seriously limits its application in the emerging fields. Although the traditional phosphate flame retardants showed excellent flame retardant efficiency in PLA, they often failed to meet the processing requirements of PLA and the thermal stability of PLA composites was decreased after their addition. Herein, an organophosphate flame retardant pentaerythritol bis(phenyl phosphonate) (PBPP) with high thermal stability and phosphorus content was synthesized by the nucleophilic substitution reaction in our laboratory. The introduction of PBPP simultaneously improved the flame retardancy, thermostability and crystallization properties of PLA. Only 3 wt% PBPP endowed PLA composites with UL-94 V-0 grade and higher LOI of 28.3% due to its excellent gas phase effect. Moreover, the crystallinity of PLA/PBPP4 was enhanced from 14.2% of PLA to 32.2% with the improvement of 127%. Because of the similar structure and good compatibility between organophosphate flame retardant and PLA matrix, flame retardant PLA/PBPP maintained almost the same strength as neat PLA. This study provided a novel way for the preparation of a high-performance flame retardant PLA composites with excellent comprehensive properties and it was important to expand the application value of multifunctional PLA materials.     

Influence of nano silica hybrid expandable graphite on flammability,thermal stability,and mechanical property of polypropylene/polyamide 6 blends

Silica (SiO₂) nanohybrid expandable graphite (nEG) particles fabricated through one-step method are used as an efficient flame retardant for polypropylene (PP)/polyamide 6 (PA6) blends. The effect of nEG on the flammability, thermal stability, crystallization behaviors, and mechanical properties of PP/PA6 composites is investigated by using limit oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared, scanning electron microscopy, and mechanical tests. Compared with pure expandable graphite (EG), nEG improves the flame retardancy of composites. The results of LOI show that LOI of PP/PA6/nEG10 and PP/PA6/nEG15 composites are 26.0% and 27.2%, respectively. But the LOI values of PP/PA6/EG10 and PP/PA6/EG15 composites are 25.7% and 26.9%, respectively. The UL-94 test results show that PP/PA6/nEG10 composites reach V-1 level when the nEG content is only 10%. However, the PP/PA6 composites with 10% EG does not pass the UL-94 test. In addition, PP/PA6 composites with 15% nEG can reach V-0 level. The CCT results further show that nEG has a higher flame-retardant efficiency than pure EG for PP/PA6 blends. The thermal stability of PP/PA6/nEG composites is better than that of PP/PA6/EG composites. The mechanical property tests indicate that nEG is more conducive to maintain the tensile and impact strengths of PP/PA6 blends than EG due to the enhanced compatibility and interfacial adhesion.     

Preparation of thermally stable and flame-retardant sugarcane bagasse-ammonium dihydrogen phosphate/epoxy composites and their performance

Epoxy resin was often applied in fiber-reinforced composite materials, adhesives, and encapsulation materials. However, epoxy was easily flammable and limited its usage in certain applications. The study recycled and reused agricultural waste sugarcane bagasse to prepare a halogen-free bio-based intumescent flame retardant and then mixed with epoxy resin to prepare a composite containing polymer with improved thermal properties and flame retardancy of the materials. The work followed the concept of circular economy and sustainability. Bagasse-ammonium dihydrogen phosphate (ADP) flame retardant was added to an epoxy resin to prepare epoxy/bagasse-ADP composites, an effective flame-retarding composite material through hydrothermal method. Adding bagasse-ADP increased the thermal stability and flame retardancy of the composite materials compared with that of pure epoxy. For the material with 30 wt% added bagasse-ADP, the char yield was 32.3 wt%, which was 18.2 wt% higher than that of pure epoxy (14.1 wt%) through thermogravimetric analysis. In addition, the limiting oxygen index increased from 21% to 30%, and the UL-94 classification improved from “Fail” to “V-0.” This performance was attributed to the nitrogen, phosphorus, and silicon content of the flame retardant.