三聚氰胺-甲醛树脂微胶囊包覆聚磷酸铵阻燃PP的性能

通过原位聚合法制备三聚氰胺-甲醛树脂(MF)微胶囊包覆聚磷酸铵(APP)粒子,研究了APP粒径对微胶囊化APP(MCAPP)结构与性能的影响。将两种MCAPP(APP平均粒径分别为5,15μm)添加至聚丙烯(PP)基体中,研究了PP/MCAPP阻燃材料的性能。结果表明:不同粒径的APP均能成功被MF包覆,且包覆后的APP粒子的水溶性均大幅下降。PP/MCAPP阻燃材料的耐渗析性和极限氧指数均得到一定程度的提高。粒径小的APP有利于MF的包覆,包覆结构层更完整。MF和APP有很好的协同作用,在APP包覆不完全的情况下,能更有效地发挥两者的相互作用,提高PP复合材料的阻燃性。     

磷系阻燃剂FR/APP协效阻燃PP

采用氧指数测定仪、热重分析仪和锥形量热仪研究了磷系阻燃剂1,3,5-三(5,5-二甲基-1,3-二氧杂环己内磷酸基)苯(FR)和聚磷酸铵(APP)复配体系对聚丙烯(PP)材料阻燃性能的影响.结果表明,FR/APP提高了PP的极限氧指数(LOI)、热稳定性和残炭率,降低了热释放速率.当w(FR)为15%和w(APP)为10%复配阻燃PP时,复合材料的LOI为29.6%.阻燃级别达到UL 94 V-0级.     

笼状磷酸酯微胶囊/聚磷酸铵阻燃聚丙烯

将笼状磷酸酯微胶囊(ET)与聚磷酸铵(APP)复配用于阻燃聚丙烯(PP)。采用氧指数和UL 94评价了阻燃PP的阻燃性能,采用热重分析、扫描电子显微镜照片、傅里叶变换红外光谱及X射线电子能谱研究了阻燃剂的协同效应和阻燃机理。结果表明:ET与APP有较好的复配协同效应,ET/APP的阻燃性能随m(ET)/m(APP)的不同而变化。当m(ET)/m(APP)为1∶2时,阻燃效果最好。w(ET/APP)为30%时,氧指数达29.7%,且达到UL 94 V-0级。     

Studies on intumescent flame retardant polypropylene composites based on biodegradable wheat straw

Wheat straw (WS) has numerous advantages compared with traditional bioadditives such as starch and lignin. So in this work, based on WS and silica microencapsulated ammonium polyphosphate, flame retardant polypropylene/wheat straw (WSP) composites were prepared by melted blend method. Flame retardant and thermal properties of WSP composites have been investigated. The results of cone calorimeter show that peaks of heat release rate and total heat release of the flame retardant WSP composite decrease substantially compared with those of pure polypropylene. The peak of heat release rate value of the flame retardant WSP composite decreases from 1290.5 to 247.9 kW/m², and the total heat release value decreases from 119.4 to 46.3 MJ/m². Meanwhile, thermal degradation and gas products of the flame retardant WSP composite were monitored by thermogravimetric analysis and thermogravimetric analysis‐infrared spectrometry. The result of thermal analysis shows that the flame retardant WSP composite has a high thermal stability and has a 30.0 wt% residual char at 600°C. From this work, we hope to provide a method to prepare flame retardant polymer composites with a biodegradable natural material‐WS.     

Inorganic–organic hybrid coating‐encapsulated ammonium polyphosphate and its flame retardancy and water resistance in epoxy resin

A novel encapsulated ammonium polyphosphate (APP) with an inorganic–organic hybrid coating (MAPP) was prepared by a sol–gel method using tetraethoxysilane and octyltriethoxysilane as precursors. The properties of MAPP were investigated by water solubility, hydrophobicity, and morphological determination. The structure of MAPP was characterized by X‐ray photoelectron spectroscopy. The flame retardancy of epoxy resin composite with MAPP was evaluated by limiting oxygen index, UL‐94 test, and cone calorimetry test. The results showed that both tetraethoxysilane and octyltriethoxysilane hydrolyze and condense to form a dense polysiloxane layer structure on the surface of APP. The water solubility of MAPP was reduced from 0.64 to 0.13 g/100 mL of water, and the water resistance of epoxy resin composites filled with MAPP was also greatly improved. The limiting oxygen index, UL‐94 test, and cone calorimeter results showed that the epoxy resin composites filled with MAPP had better flame retardancy, probably because of a synergistic effect between polysiloxane and APP. Copyright © 2013 John Wiley & Sons, Ltd.     

氧化铋协同膨胀阻燃聚丙烯的热降解机理

以Bi2O3为阻燃协同剂,采用聚磷酸铵(APP)和双季戊四醇复配阻燃体系,制备了具有良好阻燃性能的膨胀阻燃聚丙烯(PP)。Bi2O3的用量为0.10 phr时,膨胀阻燃PP的极限氧指数达25.2%,拉伸强度达28.2 MPa。Bi2O3使APP的热失重速率明显降低,高温质量保持率显著提高;高温时,Bi2O3与APP分解产生的多聚磷酸发生反应,形成Bi—O—P,提高了多聚磷酸的热稳定性。研究表明:燃烧过程中Bi2O3与APP相互作用,生成Bi的磷酸盐,抑制了多聚磷酸分解产生P2O5,使更多的多聚磷酸参与酯化反应,促进体系燃烧成炭,从而形成更加致密的膨胀炭层,提高PP阻燃性能。     

基于废弃聚氨酯泡沫为碳源的膨胀型阻燃EVA的燃烧性能

以废弃聚氨酯泡沫(WPU)为碳源、聚磷酸铵(APP)为酸源和气源、乙烯-乙酸乙烯共聚物(EVA)为基体树脂制备EVA/WPU/APP复合材料,并采用极限氧指数仪、垂直燃烧仪、锥形量热仪、烟密度测试仪研究了WPU与APP的配比对EVA/WPU/APP复合材料燃烧性能和生烟量的影响。结果表明:EPA3[w(WPU),w(APP)分别为12%,18%]与EPA4[w(WPU),w(APP)分别为6%,24%]的极限氧指数分别为28.8%,29.8%,且UL94测试均达V-0级。与其他试样相比,EPA3的热释放速率、总释放热等均最低。点火条件下,EPA4的比光密度最高;而未点火条件下,WPU不能提高EVA/WPU/APP复合材料的比光密度。     

膨胀阻燃三元乙丙橡胶/聚丙烯热塑性硫化胶的性能

分析了膨胀型阻燃剂聚磷酸铵(APP)、季戊四醇(PER)的加入方式对三元乙丙橡胶(EPDM)/聚丙烯(PP)体系硫化特性的影响,研究了加入不同膨胀型阻燃剂及协效剂硼酸锌(ZB)、有机蒙脱土(OMMT)对动态硫化EPDM/PP热塑性硫化胶(EPDM/PPTPV)性能的影响。结果表明,在动态硫化前加入APP或PER时,EPDM/PP体系不能进行硫化;当APP的加入量为30份时,EPDM/PPTPV的综合力学性能较佳;在EPDM/PPTPV中同时加入APP、PER、三聚氰胺(MEL)时,随着三者加入量的增加,体系的阻燃性能增强,但拉伸强度明显降低,三者的最佳用量为30份APP、10份PER、10份MEL,此时体系的黏度与纯EPDM/PPTPV相当;加入ZB或OMMT时,EPDM/PPTPV的拉伸强度降低,且加入OMMT体系的阻燃效果优于加入ZB体系;加入OMMT时,在低剪切速率下,体系的黏度减小;在高剪切速率下,体系的黏度增大;加入ZB时,在低剪切速率下,体系的黏度与未加ZB体系相当;在高剪切速率下,体系的黏度增大。     

Study on surface modification and flame retardants properties of ammonium polyphosphate for polypropylene

Microencapsulation ammonium polyphosphate used as flame‐retardant in polypropylene was prepared with hydroxyl silicone oil (HSO) and melamine‐formaldehyde (MF) resin in this article. Fourier transform infrared and energy dispersive spectrometer were used to identify the structure of HSO‐MFAPP. For the HSO‐MFAPP/polypropylene (PP) composites, the flame retardant effect was evaluated by the limiting oxygen index and UL‐94 testing, the compatibility was observed with scanning electron microscope, and the thermal stability was studied by thermogravimetric analysis. The results showed that the microencapsulation of ammonium polyphosphate (APP) with HSO‐MF was prepared by in situ polymerization, and the flame retardant properties and water resistance of the PP/HSO‐MFAPP/pentaerythritol (PER) composites were much better than the ones of the PP/APP/PER composites. Moreover, the compatibility of HSO‐MFAPP with PP was better than that of unmodified APP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

膨胀型阻燃剂在聚丙烯中的应用

对自制的膨胀型阻燃剂(IFR)进行了预处理并添加了协效阻燃剂等助剂,形成一种高效的膨胀型阻燃体系。通过氧指数、热重分析和扫描电子显微镜等检测手段,考察了该阻燃体系的阻燃性能和添加量。IFR、硼酸锌和其他助剂最佳质量比为25：2：2。改进后的膨胀型阻燃体系用于聚丙烯,不仅阻燃性能优良,同时还具有较好的力学性能。     

Phosphorylated sodium alginate/APP/DPER intumescent flame retardant used for polypropylene

Flame-retardant polypropylene (FR-PP) materials are realized by use of natural-sourced flame-retardant materials. Phosphorylated sodium alginate, ammonium polyphosphate, and dipentaerythritol are used to create an intumescent flame retardant (IFR). This realized flame retardant is embedded into polypropylene (PP) through melt blending method. The components, chemical structures, thermal properties, and degradation mechanisms of the samples are characterized by infrared spectrometry, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and cone calorimeter test. The results indicate that an effective IFR is obtained due to gas phase and condensed phase synergistic flame-retardant ability during combustion and degradation of FR-PP. This work presents a facile method for preparing FR-PP with efficient flame retardancy. This study is a first proof of concept for an innovative flame retardant, which could find application in future in the fields of automotive industry and the construction of electronic devices. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47794.     

Reactive extrusion to synthesize intumescent flame retardant with a solid acid as catalyst and the flame retardancy of the products in polypropylene

Reactive extrusion and solid acid catalysis technologies were adopted in the pentaerythritol–melamine phosphate (PER‐MP) reaction to synthesize intumescent flame retardant, melamine salt of pentaerythritol phosphate (MPP), which was applied in flame retardant polypropylene (PP). This environment‐friendly synthesis method provided a solution to the problems of conventional methods. On one hand, reactive extrusion in a twin screw extruder can effectively mix and transfer viscous materials that usually results in a tough stir in a conventional reactor, and achieve a continuous synthesis process. On the other hand, the solid acid, silicotungstic acid (STA) serving as a catalyst, can maintain a satisfactory conversion even with a low extrusion temperature and a short residence time, thus effectively suppressing foaming in the process of the reaction. Furthermore, without removal like other catalysts in general chemical reactions, STA was kept in produced MPP to constitute a synergism flame retardant system, therefore further improved the flame retardancy. LOI and UL94 test showed that the STA‐catalyzed MPP (by reactive extrusion) possessed much better flame retardancy in PP when compared with the noncatalyzed MPP (by reactive extrusion), as well as present commercial MPP (by POCl₃ method). In our investigation, the catalytic and synergistic effects of STA, as well as the related factors of the reactive extrusion affecting the conversion of the PER‐MP reaction, flame retardancy and mechanical performance of the corresponding flame retardant PP, were systematically investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The mechanical properties and thermal performances of polypropylene with a novel intumescent flame retardant

A novel intumescent flame retardant: tetra‐spirophosphoryl‐benzoguanamine (TSPB) containing three constituents was used as a new flame retardant for polypropylene to prepare flame‐retardant materials, whose flammability and thermal behavior were studied by the limited oxygen index (LOI), thermogravimetric analysis (TGA), in addition whose mechanical properties were investigated in this work. It was found that when the addition of TSPB was 25 wt %, the LOI value of the PP could achieve to 29.5 and pass the UL‐94 V‐0 rating test. The TGA data showed that TSPB could enhance the thermal stability of PP and effectively increase the char residue formation. The mechanical performance test showed that the addition of TSPB improve the mechanical performances of PP to some extent. Thus, the trinity intumescent flame retardant TSPB is good to modify PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

新型磷氮溴复合阻燃剂的制备及其阻燃聚丙烯的研究

以氢溴酸三聚氰胺盐（MHB）、聚磷酸铵（APP）、阻燃增效协同剂2、3-二甲基-2、3-二苯基丁烷( DMDPB )3种物质为原料复配成一种新型磷溴氮复合阻燃剂,将不同复配比例的复合阻燃剂添加到聚丙烯（PP）中,对阻燃PP材料的阻燃性能、力学性能及熔体流动速率进行测试,探讨3种物质的最佳复配比;并研究了该复合阻燃剂的添加量对材料阻燃性能的影响。结果表明,当MHB：APP：DMDPB的配比为10:10:1时,为最佳复配比;当磷氮溴复合阻燃剂的添加量为2.0 %（质量分数,下同）时,其极限氧指数值为30.8 %,燃烧等级为UL 94 V-1。     

聚磷酸铵的合成及其在聚丙烯阻燃中的应用

聚丙烯具有易燃性,限制其进一步应用。以磷酸二氢铵、五氧化二磷、尿素为原料合成聚磷酸铵,然后将其应用于聚丙烯中考察其阻燃性。在氨气压力为0.5 MPa、温度295℃下反应1.5 h,停止加热,降温至150℃,得到聚磷酸铵。红外光谱和X-衍射线表明合成聚磷酸铵是I型和II型混合型。当聚丙烯复合材料中膨胀型阻燃剂质量分数为30%,极限氧指数达30.8%,通过UL-94测试。结果表明,应用聚磷酸铵为原料的阻燃剂具有较好的阻燃性能。     

高效阻燃剂聚磷酸铵的合成工艺研究

以磷酸和尿素为原料合成了高聚合度的聚磷酸铵。通过单因素实验对制备工艺进行了优化,考察了原料配比、升温速率、预聚合温度、固化温度和固化时间等对产品质量的影响,采用核磁共振法（NMR）测定了聚磷酸铵的平均聚合度,并用X射线衍射(XRD )和红外(IR)相结合的方法对产品的晶体结构进行了表征,同时测定了聚磷酸铵的溶解度和总磷含量。结果表明,最佳制备工艺条件为：n（磷酸)∶n（尿素）=1∶1.9,预聚合阶段升温速率为2～3 ℃/min,预聚合温度为130 ℃,固化温度为230 ℃,固化时间为90 min。此条件下合成的聚磷酸铵平均聚合度为114,水中溶解度为0.492 g,总磷质量分数为31.75%,XRD表征结果表明,所得产品为Ⅰ型聚磷酸铵。     

膨胀型阻燃剂在橡胶中的应用

介绍了膨胀型阻燃剂的组成及功能改进,总结了膨胀型阻燃剂在天然橡胶、三元乙丙橡胶、丁苯橡胶及氯丁橡胶中的应用进展,并对膨胀型阻燃剂的发展方向做了展望。     

Synergistic effects of fumed silica on intumescent flame‐retardant polypropylene

The synergistic effects of fumed silica on the thermal and flame‐retardant properties of intumescent flame retardant (IFR) polypropylene based on the NP phosphorus‐nitrogen compound have been studied by Fourier transfer infrared (FTIR) spectroscopy, cone calorimeter test (CCT), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), limiting oxygen index (LOI), and UL‐94 tests. The LOI and UL‐94 data show that when ≤1 wt % fumed silica substituted for the IFR additive NP can increase 2 to 4% LOI values of the PP blends and keep the V‐0 rating. The data obtained from the CCT tests indicate the heat release rates (HRR) reduce by about 23% for the PP/NP sample with 0.5 wt % fumed silica, whereas the mass loss rates (MLR) and total heat release (THR) values are much lower than those of the PP/NP samples without fume silica. The TGA data demonstrate that a suitable amount of fumed silica can increase the thermal stability and charred residue of the PP/IFR/SiO₂ blends after 500°C. The morphological structures of charred residues observed by SEM give positive evidence that a suitable amount of fumed silica can promote the formation of compact intumescent charred layers and prevent the charred layers from cracking, which effectively protects the underlying polymer from burning. The dynamic FTIR spectra reveal that the synergistic flame‐retardant mechanism of a suitable amount of fumed silica with IFR additive is due to its physical process in the condensed phases. However, a high loading of fumed silica restricts the formation of charred layers with P? O? P and P? O? C complexes formed from burning of polymer materials and destroys the swelling behavior of intumescent charred layers, which deteriorates the flame retardant and thermal properties of the PP/IFR blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Flammability,thermal stability,and mechanical properties of ethylene-propylene-diene monomer/polypropylene composites filled with intumescent flame retardant and inorganic synergists

Three kinds of inorganic particles, zinc borate (ZB), organic montmorillonite (OMMT), and expanded graphite (EG) as synergistic flame retardants, are incorporated into ethylene-propylene-diene monomer/polypropylene (EPDM/PP) composites filled with intumescent flame retardants (IFR). The effect of three synergistic flame retardants on the combustion, thermal stability, and mechanical properties of the EPDM/PP/IFR composites are investigated by limiting oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), scanning electron microscopy, mechanical property testing, and dynamic mechanical analysis (DMA). The results from LOI, UL-94, and CCT show that the synergistic effect of IFR with ZB and EG is better than IFR with OMMT in the flame retardant EPDM/PP/IFR composites. The TGA results indicate that the thermal stability and char residues of the composites is improved with the addition of inorganic particles, which is attributed to the formation of dense char layers to isolate heat flow. DMA results including storage modulus (G'), loss modulus (G"), and loss factor (tan δ) suggest that the composites with inorganic particles exhibit more rubber-filler interaction, which limits the movement of the rubber chains.     

Effectiveness of impregnation of ammonium polyphosphate fire retardant in poplar wood using microwave heating

Poplar samples were impregnated with ammonium polyphosphate fire retardant at various pressures and durations after they were pretreated with microwave heating. The effects of the pressure and duration on the flame‐retardation and smoke‐suppression properties were investigated with cone calorimeter analysis. The peak heat release rate (pk‐HRR), total heat release (THR), and total smoke product (TSP) of treated woods were measured for samples of pretreated and untreated with microwave. After the impregnation, the poplar wood showed the significant improvement in its fire resistance. Compared with non‐impregnation wood, the pk‐HRR, THR, and TSP of wood impregnated with ammonium polyphosphate at pressure of 0.4 MPa and duration of 10 min were 48.29%, 35.58%, and 68.64% less, respectively. The pk‐HRR, THR, and TSP of microwave pretreated wood was 15.89%, 5.69%, and 13.59% less than those without microwave pretreated sample. The microwave pretreatment of wood can increase fire retardant effectiveness of ammonium polyphosphate‐impregnated wood. Copyright © 2015 John Wiley & Sons, Ltd.