双层包裹聚磷酸铵微胶囊合成及其在环氧树脂中阻燃研究

采用原位聚合法制备了蜜胺树脂(MF)和环氧树脂(EP)双层包裹聚磷酸铵(APP),得到一种新型核壳结构的微胶囊阻燃剂(EMFAPP).用傅里叶红外光谱(FTIR)和扫描电镜(SEM)对微胶囊的核壳结构进行了表征;用极限氧指数(LOI)、垂直燃烧等级测试(UL 94)对EMFAPP在EP中的阻燃性能进行了研究.EMFAPP在EP基体中阻燃性能优异,当其添加量大于7%时EP/EMFAPP均通过UL 94 V-0级,LOI值达27.0%以上.与未包裹APP相比,EMFAPP耐水性明显提高;经水处理(75℃,6天)后,EMFAPP/EP仍可保持良好的阻燃性能.采用热重分析对EMFAPP及其阻燃复合物的热降解行为进行了研究,EMFAPP能够促进成炭,EP/EMFAPP(8 wt%)在700℃残炭率达16.2%,但其低温稳定性有所下降.此外,利用热失重-红外联用对EMFAPP/EP的热降解行为进行了研究,探讨相关阻燃机理.     

原位聚合法制备聚磷酸铵微胶囊及其应用的研究进展

以聚磷酸铵微胶囊阻燃剂的包覆壳材料为重点,综述了聚磷酸铵微胶囊阻燃剂的无机材料包覆、有机材料包覆、双层或多层包覆以及纳米材料包覆,总结了国内外关于原位聚合法制备聚磷酸铵微胶囊的最新研究进展。介绍了聚磷酸铵微胶囊形成过程中,包覆壳材料与聚磷酸铵的原位聚合方法及机理。并且提出了聚磷酸铵阻燃剂在材料燃烧过程中存在的协同效应。最后,结合聚磷酸铵微胶囊阻燃剂在阻燃过程中存在的问题,展望了原位聚合在微胶囊阻燃领域中的未来发展方向。     

聚磷酸铵-苯并噁嗪微胶囊的制备及其对环氧树脂燃烧性能影响

以多聚甲醛、丙烯胺、苯酚为原料,通过Mannich反应合成烯丙基型苯并噁嗪单体(Bala),并通过核磁共振氢谱(~1H-NMR)确定了其化学结构.将Bala在聚磷酸铵(APP)原位开环聚合后,制备APP微胶囊(BMAPP).傅里叶变换红外(FTIR)和静态接触角测试表明,Bala在APP表面成功聚合,并有效提高APP的疏水性,与纯APP相比,BMAPP的接触角从10.8°提高到了71.3°.将BMAPP添加到环氧树脂(EP)中,制备EP/BMAPP复合材料.通过热重分析仪(TGA)、垂直燃烧(UL-94)、极限氧指数(LOI)、锥型量热仪(CONE)和动态热机械分析仪(DMA)对EP和EP/BMAPP的热性能以及燃烧性能进行对比分析.结果显示,10%的BMAPP的成炭效果最佳,有良好的阻燃性能,可使EP的LOI值从22.6%提高到33.6%,并通过UL-94 V-0级,600°C下残炭率达26.3%.同时,BMAPP可大幅度降低EP燃烧过程中烟密度和热释放速率,提高EP的玻璃化转变温度(T_g).BMAPP/EP-10%中,PBala和APP协同后使EP热释放速率峰值(PHRR)由1247 kW·m~(-2)降低到434 kW·m~(-2),生烟速率(SPR)降低67%左右,T_g从169°C提高到了173°C.     

磷系阻燃环氧树脂研究

本文对近年来国内外9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）衍生物的合成及其应用于阻燃环氧树脂的方法进行介绍,并对所显示的阻燃性、热性能等作了概述和比较。将反应型磷系阻燃剂DOPO衍生物引入环氧树脂基体结构中形成阻燃持久、无卤、低烟、无毒、热稳定性好的新型含磷环氧树脂。     

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.     

磷化淀粉的合成及其与聚磷酸铵协效阻燃聚乳酸的性能研究

利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和马来酸酐(MA)对淀粉进行改性得到磷化淀粉(DOPOMASt),通过红外光谱(FTIR)、核磁共振谱(1H-NMR)和X射线光电子能谱(XPS)确定其结构.利用DOPOMASt作为碳源,与聚磷酸铵(APP)复配后通过熔融共混制备了阻燃聚乳酸(PLA)...     

卡拉胶包覆APP微球阻燃水性环氧树脂

以氯化钡提纯k-卡拉胶, 经过氧化氢降解, 通过反相乳液聚合的方式制备了一系列卡拉胶包覆聚磷酸铵(APP)阻燃微球(k-CM/APP); 将其加入到水性环氧树脂(EP)中, 制备了3种钢结构防火涂层EP2, EP3和EP4. 利用红外光谱(IR)、 扫描电子显微镜(SEM)及元素分析(EDS)对k-CM/APP的结构及形貌进行了表征. 利用极限氧指数(LOI)、 垂直燃烧(UL-94)、 背温测试法、 热重分析(TG)、 锥形量热(CONE)、 附着力测试、 IR和SEM等方法分析了涂层的阻燃、 隔热及力学性能. 结果表明, k-CM/APP(3/1)球形结构完整, 800 ℃时的残炭量高达59.5%. 与其它阻燃涂层体系相比, 添加了k-CM/APP(3/1)的EP3防火涂层的极限氧指数达到28.5%, UL-94达到了V-0级, 60 min防火涂层耐火温度为253 ℃. 相比于纯EP涂层, EP3涂层的热释放速率峰值降低了58.26%, 总热释放量降低了20.84%, 附着力达到8.74 MPa.     

环状氯化磷腈阻燃微胶囊制备研究

通过UV界面聚合法,制备了以环状氯化磷腈为囊芯,丙烯酸酯共聚物为囊壁的阻燃微胶囊。对产物微胶囊的性质进行了系统表征,具体包括粒径及其分布、化学结构、表面形态和热稳定。结果表明:包囊提高了环状氯化磷腈的热稳定性、阻燃性,且对环氧复合材料的力学性能影响甚微。     

氧化石墨烯与Si-P低聚物在环氧树脂中的协同阻燃作用

采用Hummers方法制备了氧化石墨烯(GO),并通过扫描电镜(SEM)和原子力显微镜(AFM)对GO微观形貌进行了表征.详细研究了GO与硅磷低聚物(DMS-DOPO)在环氧树脂(EP)力学性能和阻燃性能中的协同作用.万能材料试验测试结果表明,GO和DMS-DOPO分别对拉伸强度和断裂伸长率提高效果明显,二者协同后,可使EP拉伸强度和断裂伸长率分别提高17.1%和42.2%.采用热重分析(TG)、极限氧指数(LOI)、垂直燃烧(UL-94)、锥型量热(CONE)和SEM对EP及其阻燃材料的热性能、燃烧性能以及炭层微观形貌进行了表征.EP/DMS-DOPO/GO在600℃残留量为EP的5.2倍,比EP/DMS-DOPO和EP/GO分别提高4.4%和208.6%.EP/DMS-DOPO/GO的LOI值大于30,并能通过UL-94 V-0级别,燃烧过程中可形成内部结构疏松多孔、外表面致密的膨胀炭层.DMS-DOPO和GO协同后使EP热释放速率峰值由1154 k W·m-2降低到710 k W·m-2,总烟释放量降低30%.     

Synergistic Flame Retardancy of Phosphatized Sesbania Gum/Ammonium Polyphosphate on Polylactic Acid

Phosphating sesbania gum (DESG) was obtained by modifying sesbania gum (SG) with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and endic anhydride (EA). The structure of DESG was determined using Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR). Flame-retardant polylactic acid (PLA) composites were prepared by melt-blending PLA with DESG, which acted as a carbon source, and ammonium polyphosphate (APP), which acted as an acid source and a gas source. The flame retardancy of the PLA composite was investigated using vertical combustion (UL-94), the limiting oxygen index (LOI) and the cone calorimeter (CONE) test. Thermal properties and morphology were characterized via thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM), respectively. Experimental results indicated that when the mass ratio of DESG/APP was equal to 12/8 the LOI value was 32.2%; a vertical burning test (UL-94) V-0 rating was achieved. Meanwhile, the sample showed a lowest total heat release (THR) value of 52.7 MJ/m², which is a 32.5% reduction compared to that of neat PLA. Using FESEM, the uniform distribution of DESG and APP in the PLA matrix was observed. The synergistic effect of DESG and APP effectively enhanced the flame retardancy of PLA. Additionally, the synergistic mechanism of DESG and APP in PLA was proposed.     

碳纳米管改性环氧树脂的导热和阻燃性能

以双酚A二缩水甘油醚(DGEBA)环氧树脂(Epoxy Resin,EP)为基体、甲基六氢苯酐(MHHPA)为固化剂、以多壁碳纳米管(MWCNTs)为添加剂制备了环氧树脂/碳纳米管纳米复合材料。通过对微观结构、玻璃化转变温度(Tg)、热失重、热导率和锥形量热测试结果分析,研究了质量分数少于1.5%的MWCNTs对环氧树脂的导热和阻燃性能影响,结果表明,MWCNTs质量分数为1.5%时,复合材料发生团聚;纳米复合材料随着MWCNTs质量分数的增加Tg值先增加后降低;失重5%时,对应的温度先增加后降低,残炭量增加;样品的热导率呈现先升高后降低的趋势,当MWCNTs质量分数为1%时,复合材料的热导率最大;MWCNTs加入后环氧树脂的总释热量减少,释烟量增加,阻燃性得到一定程度的提高。     

Microencapsulated Ammonium Polyphosphate with Polyurethane Shell: Application to Flame Retarded Polypropylene/Ethylene-propylene Diene Terpolymer Blends

Microencapsulated ammonium polyphosphate with polyurethane resin (PUMAPP) was prepared by in situ polymerization and characterized by X-ray photoelectron spectroscopy (XPS). The flame retardation of PUMAPP/dipentaerythritol(DPER) and ammonium polyphosphate (APP)/DPER flame retarded polypropylene (PP)/ethylene propylene diene rubber (EPDM) composites were studied using limiting oxygen index (LOI), UL-94 test and cone calorimeter. Results demonstrated that the flame retardancy of the PP/EPDM/PUMAPP/DPER composites was better than that of the PP/EPDM/APP/DPER composites at the same additive loading. Real time Fourier transform infrared (FTIR) and thermogravimetric analysis (TG) were used to study the thermal degradation and stability of the PP/EPDM/PUMAPP/DPER composite. The hydrolytic stability of the flame retarded PP/EPDM composites was studied. It was found that the microencapsulation of APP with the PU resin leaded to a decrease in the particle's water solubility. Moreover, the synergistic effect of vinyltrimethoxysilane (VTMS) on the PP/EPDM/PUMAPP/DPER composite was also investigated.     

A Well-Defined Cyclotriphosphazene-Based Epoxy Monomer and Its Application as A Novel Epoxy Resin: Synthesis,Curing Behaviors,and Flame Retardancy

Abstract

A novel cyclotriphosphazene-based epoxy monomer, hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene (HGCP), was synthesized via a four-step synthetic route, and fully characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. Thermosetting systems based on HGCP with three curing agents, for example, 4,4′-diaminodiphenylsulfone (DDS), 4,4′-diaminodiphenylmethane (DDM), and dicyandiamide (DICY), were used for making a comparison of their thermal curing behaviors. The curing behaviors were measured by differential scanning calorimetry. Moreover, flame retardancy of HGCP thermosetting systems was estimated by Limiting Oxygen Index (LOI) and Vertical Burning Test (UL-94). The resulting HGCP thermosetting systems exhibited better flame retardancy than the common epoxy resins diglycidyl ether of bisphenol A (DGEBA) and the regular brominated bisphenol A epoxy resin (TBBA) cured by DDS, respectively. When HGCP was cured by DDS, its thermosetting system gave the most char residues, met the UL-94 V-0 classification, and had a limiting oxygen index value greater than 35.     

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.     

聚苯氧基磷酸联苯二酚酯/聚磷酸铵膨胀阻燃剂对环氧树脂阻燃性能影响研究

以聚苯氧基磷酸联苯二酚酯(PBPP)与聚磷酸铵(APP)组成复合阻燃剂,对环氧树脂(EP)进行阻燃改性.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)等方法研究改性环氧树脂的阻燃性能和阻燃机理.结果表明,PBPP/APP体系对EP具有较好的阻燃性能,阻燃剂添加量为10%时能使环氧树脂的氧指数提高到29.6%,垂直燃烧等级达到UL94 V-0级,残炭量大大增加;平均热释放速率下降45.7%,热释放速率峰值下降51.0%,有效燃烧热平均值下降21.1%;TGA、CONE、SEM等综合分析显示了PBPP/APP改性后的环氧树脂比纯环氧树脂具有更高的热稳定性,燃烧后能够形成连续、致密、封闭、坚硬的焦化炭层,在聚合物表面产生有效覆盖、隔绝了氧气,改善了环氧树脂的燃烧性能.     

双酚A双(二苯基)磷酸酯对环氧树脂的阻燃性能

采用双酚A双(二苯基)磷酸酯(BDP)、有机改性蒙脱土(OMMT)和环氧树脂(EP),分别制备了阻燃环氧树脂(BDP-EP)和阻燃纳米材料(BDP-OMMT-EP).利用氧指数、水平垂直燃烧、热重分析以及锥形量热等技术探讨了阻燃材料的阻燃性能和阻燃机理.实验结果证明,BDP-EP和BDP-OMMT-EP的最大热释放速率和平均热释放速率等参数都降低了,但是BDP的阻燃效果优于BDP-OMMT,即BDP和OMMT没有协同阻燃作用.     

Water resistance,thermal stability,and flame retardation of polypropylene composites containing a novel ammonium polyphosphate microencapsulated by UV‐curable epoxy acrylate resin

In this work, ammonium polyphosphate (APP) was microencapsulated by UV‐curable epoxy acrylate (EA) resin. The resulting novel EA‐microencapsulated APP (EA‐APP) was characterized by Fourier transform infrared spectra, X‐ray photoelectron spectroscopy, X‐ray diffraction, scanning electron microscopy, granulometry, and thermogravimetric (TG) analysis. EA‐APP was used to flame retard polypropylene (PP). The water solubility of EA‐APP and the water resistance of PP/EA‐APP systems were investigated. The thermal stability and combustion behaviors of PP/EA‐APP composites were studied through TG and cone calorimeter (CC) tests, respectively. The water resistance test showed that the EA shell could significantly improve the water resistance of PP/APP. TG data illustrated that the char residue of EA‐APP greatly increased by 149% compared with uncoated APP, and the thermal stability of PP/EA‐APP composite was improved because of the microencapsulation of APP, with an increment of 248% for the char residue compared with PP/APP. CC test results indicated that the peak value of heat release rate, the total heat release, and the peak of smoke production rate of PP/EA‐APP decreased in comparison with PP/APP. The mechanism for the improvement of flame retardancy in CC test was discussed based on the experimental results. EA resin containing a large number of hydroxyl groups might promote the dehydration reaction in EA‐APP, which facilitated the formation of char residue and the stabilization of APP. Consequently, the flame‐retardant efficiency for APP was improved because of the presence of EA shell. Copyright © 2014 John Wiley & Sons, Ltd.     

Microencapsulated ammonium polyphosphate with epoxy resin shell: preparation,characterization, and application in EP system

Microencapsulated ammonium polyphosphate with an epoxy resin (EP) shell (MCAPP) was prepared by in situ method, and was characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), and thermgravimetric analysis (TGA). Compared to ammonium polyphosphate (APP), MCAPP has smaller particle sizes and lower water solubility. The effect of MCAPP on the fire performance of EP was studied by using limiting oxygen index (LOI) and UL‐94 tests. When the same loading levels of APP or MCAPP were added into EP, the LOI and UL‐94 tests show similar results. Tensile, bending, and impact strengths of the EP/APP and EP/MCAPP composites were also evaluated, and the results indicate that MCAPP has much less negative influence on the mechanical properties than APP. Copyright © 2010 John Wiley & Sons, Ltd.