透明阻燃环氧树脂的制备及研究

合成了一种新型含磷单体。以甲基二氯磷和双酚A为单体,通过熔融缩聚合成了分子量为1 316的聚甲基亚膦酸双酚A酯(PMPBE)。将合成的聚甲基亚膦酸双酚A酯添加环氧树脂(EP)中,制备了不同添加量的透明阻燃复合材料。通过极限氧指数仪、垂直燃烧仪、微型量热仪、扫描电子显微镜等测试了EP/PMPBE复合材料的结构和性能。结果表明,PMPBE和EP在120℃发生化学反应,得到的样条有良好透明性和热稳定性,与EP相容性好,说明PMPBE是良好的反应型阻燃剂。当添加20%PMPBE时,EP的极限氧指数从17.0%提高到27.6%,达到V-0级,最大放热速率和总热释放量均降低27.0%左右,能明显抑制EP的分解,提高EP的阻燃性能,以凝聚相机理实现阻燃。     

新型无卤阻燃环氧树脂复合材料的制备及阻燃性能

双酚A二缩水甘油醚型环氧树脂(EP)作为基材,添加新型阻燃剂双酚A-双(5,5-二甲基-1,3-二氧杂己内磷酸酯)(以下简称FR),制备不同组分的样品(FR/EP体系)。采用氧指数分析,垂直燃烧试验测试以及锥形量热仪对样品进行表征。结果表明:FR25%/EP体系氧指数达30.6%,接近难燃级别,FR20%/EP体系垂直燃烧试验测试达到V-0级别,经锥形量热仪测试FR20%/EP体系阻燃性能最优。     

两种磷系阻燃剂阻燃聚氨酯硬泡的对比研究

通过箱式发泡法制备了含有添加型阻燃剂甲基膦酸二甲酯与反应型阻燃剂聚磷酸酯多元醇OP550的聚氨酯硬泡(RPUF)。利用热重分析仪、氧指数仪、锥形量热仪研究了体系中阻燃剂质量分数均为10%的情况下,两种不同类型阻燃剂的添加比例对聚氨酯硬泡热性能与阻燃性能的影响。结果表明,同时添加两种阻燃剂可提高聚氨酯硬泡在高温下的残炭率,当甲基膦酸二甲酯O∶P550=4 1∶(质量比)时,体系的氧指数可达24.4%,且热释放速率的峰值达到最低值144.51 kW/m2。此外,对两种阻燃剂的阻燃机理进行了初步的探讨。     

新型反应型磷-氮阻燃剂的合成与应用

采用膦酸酐和苯胺为原料,通过一步法合成了一种含N-P的具有反应活性的β-（N-苯基酰胺）乙基甲基次膦酸(CEMP),通过FTIR和1H-NMR对其结构进行了表征。初步探讨了CEMP在环氧树脂(EP)中的应用。结果表明:CEMP是一种有效的EP阻燃剂,当阻燃剂添加量为20 %(质量分数,下同)时即可满足UL94-V0的阻燃等级,极限氧指数达到29.4 %,弯曲强度比未阻燃的EP有了较大的提高,但玻璃化转变温度（Tg)）有所下降。     

阻燃PET的燃烧性能研究

用氧指数仪、CONE锥形量热仪研究了含卤磷酸酯(A)、芳香族溴化物(B)、含溴聚合物阻燃剂(C)三种新型阻燃剂在添加量分别为5％、10％、15％时对PET燃烧性能的影响。研究结果表明三种阻燃剂的加入均使PET的极限氧指数明显提高,且从CONE实验结果显示:阻燃样品的热释放速率HRR较未阻燃的纯样品有了显著降低,且三种阻燃剂的加入均使PET的发烟量有所下降。     

无卤阻燃ABS复合材料的研究

以磷/硅阻燃剂(SPDV)和有机蒙脱土(OMMT)为阻燃剂,通过熔融共混制备无卤阻燃丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料.通过锥形量热仪、极限氧指数和UL94垂直燃烧仪测试复合材料的阻燃性能.结果表明:随着SPDV添加量的增加,ABS复合材料的阻燃性能逐渐改善,OMMT的加入降低了材料燃烧的生烟速率;当SPD...     

无卤阻燃低密度聚乙烯复合材料的流变性能

采用熔融共混法制备了无卤阻燃低密度聚乙烯(LDPE/FR)复合材料。通过极限氧指数仪和毛细管流变仪等考察了LDPE/FR复合材料的阻燃性能和流变性能。结果表明:随着阻燃剂添加量的增加,LDPE/FR的阻燃性能逐渐提高,当阻燃剂的质量分数为25%时,阻燃体系的极限氧指数达28.3%;LDPE/FR熔体的表观黏度随着阻燃剂添加量的增加以及剪切速率的提升而降低,其非牛顿指数为0.42~0.70,属于典型的假塑性流体。     

含磷杂菲侧基双酚A酚醛树脂的合成与应用

基于酚醛树脂反应,以二磷杂菲丙基双酚A(DDBA)和甲醛为原料,合成了一种含磷杂菲侧基的二磷杂菲丙基双酚A甲醛树脂(PDBA).通过傅里叶变换红外光谱仪、核磁共振氢谱仪和凝胶渗透色谱仪等证明了产物PDBA的结构.将PDBA和DDBA作为反应型阻燃剂用于环氧树脂(EP)阻燃改性,通过极限氧指数仪、垂直燃烧试验箱、锥形量热...     

磷杂菲三嗪双基化合物阻燃环氧树脂的量效关系

将三-(DOPO-羟甲基苯氧基)-三嗪(Trif-DOPO)添加到双酚A缩水甘油醚/4,4′-二氨基二苯砜环氧树脂(EP)体系中,制备了一种无卤阻燃EP,利用差示扫描量热仪、热失重分析仪、根限氧指数(LOI)测定仪、垂直燃烧测试仪、锥形量热仪及吸水性试验测试了无卤阻燃EP的热性能、阻燃性能和吸水性能,研究了Trif-DOPO对EP性能影响的量效关系。结果表明,Trif-DOPO与环氧基体共同构成一个膨胀阻燃体系。与空白试样相比,随着体系磷质量分数从1.0%增至2.0%,阻燃试样的点燃时间、总热释放量、平均有效燃烧热、玻璃化转变温度均与Trif-DOPO的用量呈负相关性;阻燃试样锥量测试残炭的膨胀倍率与Trif-DOPO的用量呈正相关性;而阻燃试样的热释放速率峰值和平均热释放速率虽明显减小,但在研究的范围内受阻燃剂含量的影响不大。此外,随着Trif-DOPO用量的增加,试样的LOI先增大后减小,当体系磷质量分数为1.2%时,试样的阻燃性能最佳,其LOI为36.0%,垂直燃烧性能达到UL 94 V–0级。Trif-DOPO的添加还能够在一定程度上降低EP的吸水率。     

无卤阻燃增强聚对苯二甲酰癸二胺(PA10T)阻燃性能研究

采用一种次膦酸金属盐阻燃剂(FRP)对增强聚对苯二甲酰癸二胺(PA10T)进行阻燃改性。通过垂直燃烧法考察了不同阻燃剂含量下体系的阻燃性,运用极限氧指数仪测试了不同阻燃剂含量下体系的极限氧指数(LOI),并对体系燃烧后的残炭进行扫描电镜分析。结果表明,随着FRP添加量的增加,体系燃烧后的残炭量增加,炭层也变得更加致密,越容易通过UL94阻燃性测试。     

卡拉胶包覆APP/MnO2增强水性环氧树脂阻燃抑烟性能

用反相乳液法，以卡拉胶（KC）为壳材，聚磷酸铵（APP）和二氧化锰（MnO2）为芯材，制备了KC包覆APP/MnO2阻燃剂（KC-FR）。通过FTIR、 XRD、 SEM和 EDS对KC-FR进行了表征。结果表明：卡拉胶已成功包覆APP和MnO2，合成的样品具有微胶囊结构。将KC-FR应用于水性环氧树脂（EP）中，考察KC、APP、MnO2 三者质量比对EP阻燃、抑烟性能的影响。用极限氧指数（LOI）、垂直燃烧（UL-94）和锥形量热（CCT）测试了涂层的阻燃、抑烟性能。结果发现，当KC/APP/MnO2的质量比为2∶1∶1，并且在EP中添加量为20%时，制备的阻燃涂层EP2的LOI达到29.1%，UL-94达到V-0级，表现出较好的阻燃性能。EP2相比于其它涂层热释放峰值（pHRR）、热释放总量（THR）和烟释放总量（TSP）最低，相比于EP0分别下降了42%、37%和46%，表现出较好的抑烟性能。另外，热重分析（TGA）测试结果显示EP2在800℃残炭量（W800）为33%，表明KC-FR具有促进EP成炭的功能。通过SEM对残炭表面分析发现，EP2表面炭层更加致密，这表明KC-FR对促进形成稳定并且致密的炭层起到至关重要的作用。     

A (4-fluorophenyl)(phenyl)phosphine oxide-modified epoxy resin with improved flame-retardancy,hydrophobicity, and dielectric properties

The compound (4-fluorophenyl)(phenyl) phosphine oxide (4-FPO) was designed, synthesized, and used in the modification of epoxy resin (EP). The 4-FPO-modified EP was prepared by curing the reaction mixture of diglycidyl ether of bisphenol A (DGEBA) and 4-FPO in the presence of 4,4′-diaminodiphenylsulfone (DDS). Compared with the unmodified EP, the limiting oxygen index value of the EP/4-FPO-0.6 (4-FPO-modified EP with 0.6 wt% of phosphorus) increased to 31.6%, and the sample achieved UL-94 V-0 rating. The peak of the heat release rate, average of the heat release rate, and total heat release of EP/4-FPO-0.6 were reduced by 39, 24, and 19%, respectively. Mechanism study showed that the quenching effect in the gas and barrier effect in the condensed phase were responsible for the enhanced flame-retardant properties of the 4-FPO-modified EP. The results showed that hydrophobicity and dielectric properties of the modified EP were clearly improved.     

木质素与含磷阻燃剂对环氧树脂固化物阻燃性能的影响

利用不同质量比的木质素、苯酐（PA）、环氧树脂（EP）、2-（二苯基磷酰基）琥珀酸（DPPOSA）共固化制备出一系列环氧树脂固化物,采用极限氧指数测试、UL-94垂直燃烧评级测试、锥形量热仪热释放速率和总热释放量测试、空气条件下的热重分析测试和扫描电镜对环氧固化物进行测试和分析。当EP为90.0%、PA为6.5%、DPPOSA为2.0%、木质素为1.5%时制备的环氧固化物（P-12）的热稳定性能和阻燃性能得到了明显的改善。阻燃性能测试表明：其极限氧指数（LOI）达到34.6%,垂直燃烧测试通过UL-94的V-0级,热释放速率和热释放总量也有效降低;热降解测试结果表明：DPPOSA和木质素的加入可以使材料的降解时间提前,成炭能力增强;扫描电镜结果显示：添加DPPOSA和木质素的环氧固化物燃烧后形成连续、均一、紧密的炭层,进一步证明DPPOSA和木质素的加入使环氧固化物的成炭能力得到增强。     

Ionic liquid modified graphene oxide for enhanced flame retardancy and mechanical properties of epoxy resin

In this work, to improve its dispersion and flame retardancy, graphene oxide (GO) was functionalized by silane coupling agent KH550 and 1-butyl-3-methylimidazole hexafluorophosphate (PF₆-ILs), and characteristics of the PF₆-ILs@GO was obtained by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Then, the synergistic flame retardant of GO or PF₆-ILs@GO and melamine pyrophosphate (MPP) were applied for epoxy resin (EP) materials. Specifically, the limiting oxygen index (LOI) value of EP with 0.1 wt% PF₆-ILs@GO was increased to 29.2% from 27.5% of EP/MPP composites, and the UL-94 test reached the V-0 rating. The CCT results showed that the total heat release (THR) and total smoke release (TSP) of EP/MPP/PF₆-ILs@GO composites were significantly 24.4% and 53.4% lower than that of EP/MPP composites. Besides, the thermal behavior investigated by TGA indicated that the char-forming effect of GO and PF₆-ILs@GO was great, the residual char of EP/MPP/PF₆-ILs@GO composites was as high as 19.5% at 700°C, and its thermal stability was higher than that of EP/MPP composites. On the other hand, the tensile strength of EP/MPP/GO and EP/MPP/PF₆-ILs@GO composites were increased by 15.6% and 28.3% compared with EP/MPP composites. According to SEM analysis, the EP/MPP/GO composites formed a good protective char layer, which can effectively improve flame retardancy of EP. This research represents a new method of flame retardant modified GO to improve the flame retardancy and mechanical properties of polymers.     

Synthesis of aluminum ethylphenylphosphinate flame retardant and its application in epoxy resin

A novel flame retardant additive, aluminum ethylphenylphosphinate (AEPP), was synthesized from diethyl phenylphosphonite and aluminum chloride hexahydrate, and characterized by FTIR, ¹H NMR, and ³¹P NMR. AEPP was added into diglycidyl ether of bisphenol A epoxy resin (EP) cured by bisphenol A‐formaldehyde novolac resin. The flame retardancy of the cured EP was investigated by limited oxygen index, UL 94 test, and cone calorimeter test. The results revealed that the EP composite containing 15% AEPP had a limited oxygen index value of 28.2% with a UL 94 V‐0 rating. The incorporation of AEPP effectively decreased the peak heat release rate and the total heat release in cone calorimeter test analysis. Scanning electron microscopy results showed that the introduction of AEPP benefited to the formation of a smooth and continuous char layer during combustion of the flame retarded EP. The thermogravimetric analysis results indicated that the incorporation of AEPP promoted the initial decomposition of EP matrix, but AEPP/EP composites had a higher char yield at high temperatures. Moreover, the flexural properties of the flame retarded EP composites were studied.     

Synthesis of phosphaphenanthrene derivatives as flame retardants and their properties in epoxy resin composites

In order to further improve the flame-retardant properties of epoxy resins (EPs), two hydroxyl-containing phospha-phenanthrene derivatives, DOPO-PHBA and DOPS-PHBA, were prepared from the molecular structure design by using 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide (DOPO), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide (DOPS), and 4-hydroxybenzaldehyde (PHBA) as the raw materials. These composites of DOPO-PHBA/EP and DOPS-PHBA/EP were prepared by melt blending. The results showed that UL-94 V-0 was achieved with an LOI of 31.9% when just 7.5% DOPS-PHBA was added to EP, while a limited oxygen index of 35.2% was achieved with 10% DOPO-PHBA/EP. Moreover, in comparison with 7.5% DOPO-PHBA/EP, 7.5% DOPS-PHBA/EP has the lower peak of heat release rates, total heat release values, and fire growth rate, demonstrating that the flame-retardant DOPS-PHBA is more effective at reducing heat release, enhancing the material's flame retardancy, and lessening the intensity of EP burning. The Thermogravimetric-infraredspectrometry (TG-IR) results showed that the phosphorus-containing radicals generated by DOPS-PHBA/EP pyrolysis trapped the free radicals, such as H˙, O˙, or HO˙, thus providing free radical quenching. Furthermore, combining the macro and micro Scanning electron microscopy (SEM) test results, DOPS-PHBA/EP has a better char formation ability and a denser char layer, which can play a better role in heat and oxygen insulation.     

Preparation and investigation of flame‐retardant epoxy resin modified with a novel halogen‐free flame retardant containing phosphaphenanthrene,triazine‐trione,and organoboron units

In this article, a novel flame retardant (coded as BNP) was successfully synthesized through the addition reaction between triglycidyl isocyanurate, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and phenylboronic acid. BNP was blended with diglycidyl ether of bisphenol‐A to prepare flame‐retardant epoxy resin (EP). Thermal properties, flame retardancy, and combustion behavior of the cured EP were studied by thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the flame retardancy and smoke suppressing properties of EP/BNP thermosets were significantly enhanced. The LOI value of EP/BNP‐3 thermoset was increased to 32.5% and the sample achieved UL94 V‐0 rating. Compared with the neat EP sample, the peak of heat release rate, average of heat release rate, total heat release, and total smoke production of EP/BNP thermosets were decreased by 58.2%–66.9%, 27.1%–37.9%, 25.8%–41.8%, and 21.3%–41.7%, respectively. The char yields of EP/BNP thermosets were increased by 46.8%–88.4%. The BNP decomposed to produce free radicals with quenching effect and enhanced the charring ability of EP matrix. The multifunctional groups of BNP with flame retardant effects in both gaseous and condensed phases were responsible for the excellent flame retardancy of the EP/BNP thermosets. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45291.     

Flame retardant and mechanical properties of epoxy composites containing APP−PSt core−shell microspheres

Ammonium polyphosphate (APP)–polystyrene (PSt) core–shell microspheres (CSPs) were synthesized via in situ radical polymerization. The core–shell structure was confirmed by transmission electron microscope (TEM). The results of optical contact angle measurements demonstrated a significant improvement in hydrophobicity of the modified APP. The obtained APP–PSt CSPs were added into epoxy (EP) system with various loadings. Effects of CSP on flame retardancy, thermal properties, heat release rate (HRR), smoke production, and mechanical properties of EP/CSP composites were investigated by limiting oxygen index (LOI), UL‐94 tests, thermogravimetric analysis (TGA), cone calorimeter, and tensile test. LOI and UL‐94 indicated that CSP remarkably improved the flame retardancy of EP composites. TGA showed that the initial decomposition temperature and the maximum‐rate decomposition temperature decreased, whereas residue yields at high temperature increased with the incorporation of microspheres. Cone calorimetry gave evidence that HRR, peak release rate, average HRR, and smoke production rate of EP/CSP composites decreased significantly. The morphology of char residues suggested that CSP could effectively promote EP to form high‐quality char layer with compact outer surface and swollen inner structure. Tensile strength of EP was enhanced with the addition of CSP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40218.     

Synthesis of a novel phosphonate flame retardant and its application in epoxy resins

A novel phosphonate flame retardant additive bis(2,6‐dimethyphenyl) phenylphosphonate (BDMPP) was synthesized from phenylphosphonic dichloride and 2,6‐dimethyl phenol, and its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy, ¹H and ³¹P nuclear magnetic resonance. The prepared BDMPP and curing agent m‐phenylenediamine were blended into epoxy resins (EP) to prepare flame retardant EP thermosets. The effect of BDMPP on fire retardancy and thermal degradation behavior of EP/BDMPP thermosets was investigated by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter and thermalgravimetric analysis (TGA). The morphologies of char residues of the EP thermosets were investigated by scanning electron microscopy (SEM) and the water resistant properties of thermosets were evaluated by putting the samples into distilled water at 70°C for 168 h. The results demonstrated that the cured EP/14 wt % BDMPP composites with the phosphorus content of 1.11 wt % successfully passed UL‐94 V‐0 flammability rating and the LOI value was as high as 33.8%. The TGA results indicated that the introduction of BDMPP promoted EP matrix decomposed ahead of time compared with that of pure EP and led to a higher char yield at high temperature. The incorporation of BDMPP enhanced the mechanical properties and reduced the moisture absorption of EP thermosets. The morphological structures of char residue revealed that BDMPP benefited to the formation of a more compact and homogeneous char layer on the materials surface during burning, which prevented the heat transmission and diffusion, limit the production of combustible gases and then lead to the reduction of the heat release rate. After water resistance tests, EP/BDMPP thermosets still remained excellent flame retardancy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42765.     

Flame retardant properties of polyamide 6 with piperazine pyrophosphate

Piperazine pyrophosphate (PAPP) was mixed in polyamide 6 (PA6) to investigate its flame retardant properties. The PAPP was characterised by Fourier transform infrared (FT-IR), elemental analysis, proton nuclear magnetic resonance (1H-NMR) spectroscopy and thermogravimetric analysis (TGA). The elemental analysis and TGA results of PAPP indicated it had a high P element content and good thermal stability. The flame retardancy of PA6/PAPP was also characterised by TGA, limiting oxygen index (LOI), UL-94 vertical test and microscale combustion calorimetry (MCC). The TGA results showed that the PAPP increased the stability of the PA6/PAPP and resulted in a significant increase of char residue. PA6/PAPP passed the UL94 V-0 rating with a LOI value of 42 vol %. The MCC test indicated that the PAPP can greatly decrease the peak heat release rate (PHRR) and total heat release (THR). The results of scanning electron microscope (SEM) illustrated that PAPP can promote the formation of compact char layer.