纳米填充环氧树脂/玻璃纤维复合材料的摩擦磨损性能研究

分别将纳米三氧化二铝（Al2O3）、纳米二氧化钛（TiO2）、纳米二氧化硅（SiO2）颗粒和碳纳米管(CNTs)填充到环氧树脂(EP)/玻璃纤维(GF)复合材料中,制备了纳米填充EP/GF复合材料,GF的体积含量为30 %。用环块摩擦试验机研究了纳米填充物对EP/GF复合材料的摩擦磨损性能的影响。结果表明,1.0 %（质量分数,下同）的CNTs能够较大幅度地降低复合材料的摩擦因数和磨损率,而纳米Al2O3、纳米TiO2和纳米SiO2颗粒可以明显提高复合材料的耐磨损性能。     

可生物降解聚(3-羟基丁酸酯-co-4-羟基丁酸酯）/层状?-磷酸锆纳米复合材料的制备及性能

以可生物降解聚（3-羟基丁酸酯-co-4-羟基丁酸酯）[P(3,4)HB]为基体,有机改性层状化合物?-磷酸锆（OZrP）为增强相,采用溶液插层法制备了P(3,4)HB/OZrP纳米复合材料。分别用X射线衍射仪（XRD）、扫描电镜（SEM）、偏光显微镜（POM）、热重分析仪（TGA）和差式扫描量热仪（DSC）等对其微观结构、热稳定性、结晶行为及降解性能进行了表征与分析。研究表明,具有纳米片层结构的OZrP能均匀分散在P(3,4)HB基体中形成纳米复合结构,OZrP能通过异相成核作用促进P(3,4)HB的结晶,并能促进P(3,4)HB的降解,但降低P(3,4)HB 的热稳定性。     

微流体技术制备聚合物纳米荧光探针

摘要：设计并制作了同轴共流毛细管微反应器，选用聚（9,9-二辛基芴-共-苯并噻二唑）（PFBT）作为聚合物，四氢呋喃（THF）作为溶剂，去离子水作为反溶剂，聚苯乙烯－马来酸酐共聚物（PSMA）作为稳定剂，结合纳米沉淀法制备聚合物纳米荧光探针，并使用动态光散射(DLS)进行表征。结果显示，在操作条件相同，通道尺寸分别为50 μm～500 μm时，通道尺寸越小，越有利于制备小粒径的纳米颗粒；当PFBT的质量浓度为1 μg/mL～50 μg/mL时，聚合物质量浓度越低，越有利于制备小尺寸的纳米颗粒；当通道尺寸为50 μm，PFBT质量浓度为5 μg/mL，去离子水与聚合物溶液的流量比达到40时，纳米颗粒的尺寸可下降到14 nm，实现了对纳米颗粒尺寸的精确控制并制备了尺寸更小的聚合物纳米颗粒。     

聚合物/纳米石墨微片复合材料的研究进展

详述了纳米石墨微片（NanoG）的制备工艺、结构特征,重点归纳总结了纳米石墨微片与聚甲基丙烯酸甲酯（PMMA）、聚苯胺(PANI)、聚苯乙烯(PS)以及聚吡咯(PPy)复合材料的复合方法、性能及应用情况。最后对聚合物/纳米石墨微片复合物制备工艺问题,纳米石墨微片在聚合物中的分散性问题以及如何提高聚合物/纳米石墨微片复合物的导电性问题进行了展望,同时提出改性的纳米石墨微片与聚合物复合的应用研究将是一个崭新的研究领域。     

纳米SiO2促进P(MMA-co-MAA)自脆裂 剥离性能

通过纳米二氧化硅（SiO2）对甲基丙烯酸甲酯-甲基丙烯酸共聚物〔P(MMA-co-MAA) 〕乳液进行了复配改性。采用红外光谱（FTIR）、热重（TG）、X射线衍射仪（XRD）¬、扫描电镜（SEM）对复合乳液的结构和性能进行了测定。结果表明,加入纳米SiO2后使得P(MMA-co-MAA)的聚集态结构发生了改变,造成乳液自脆化形貌发生变化。主要表现为,随着纳米二氧化硅含量的增加,脆片有变大的趋势,同时,收缩卷曲更加明显,提高了P(MMA-co-MAA)的自脆裂剥离性能。这种性能在去除设备表面的放射性污染的废物机械回收中更具备优势     

rGO-SnO2纳米复合物制备及室温下NH3气敏性能

采用沉淀-焙烧法制备了室温下对NH3具有高灵敏度和高选择性的rGO-SnO2纳米复合材料。利用X射线衍射（XRD），傅里叶红外光谱（FTIR），X射线光电子能谱（XPS），扫描电子显微镜（SEM），透射电子显微镜（TEM）和比表面积（BET）表征分析了纯SnO2与rGO(1.0%)-SnO2纳米复合物的属性。与纯SnO2相比，rGO(1.0%)-SnO2纳米复合物中SnO2晶体尺寸较小，约为6~20nm，比表面积更大，为33m2/g；rGO(1.0%)-SnO2纳米复合材料对0.01% NH3的灵敏度达到了49.6%，是相同NH3浓度下纯SnO2灵敏度的2.1倍，并且响应和恢复时间分别为21s和204s，比纯SnO2缩短了24s和10s，具有良好的重复性，选择性与稳定性；rGO(1.0%)-SnO2纳米复合材料优良的气敏性能是由rGO与SnO2产生的p-n异质结以及溶解的NH3电离出导电离子共同作用的结果。     

单分散纳米二氧化硅微球表面化学修饰与表征

通过溶胶-凝胶法制备纳米二氧化硅微球,以乙醇作为分散介质,用硅烷偶联剂采用一步法对纳米二氧化硅进行了表面化学修饰。通过X-射线光电子能谱（XPS）、透射电子显微镜（TEM）和傅立叶红外光谱仪（FT-IR）等手段对其改性前后效果进行了分析。研究发现修饰后的纳米二氧化硅微球的疏水性增强;硅烷偶联剂与纳米二氧化硅表面羟基发生了化学反应。     

燕麦β-葡聚糖—酪蛋白—玉米醇溶蛋白纳米粒子的制备及其负载α-硫辛酸

通过反溶剂共沉淀法制备出以玉米醇溶蛋白（Zein）包埋α-硫辛酸（LA）为内核，酪蛋白酸钠和燕麦β-葡聚糖的美拉德反应聚合物（MC）为外壳涂层的LA-Zein-MC纳米粒子。利用SEM、FTIR、XRD、DSC对LA-Zein-MC纳米粒子进行了表征，并对其稳定性和胃肠道模拟进行了测试。结果表明，LA-Zein-MC纳米粒子的最佳制备工艺条件为m(Zein)∶m(LA)=25∶1、m(Zein)∶m(MC)=1∶2.4。在该条件下制备的LA-Zein-MC纳米粒子粒径为235.4 nm,Zeta电位为–32.1 mV，多分散系数为0.144，最大包封率为56.17%，载药量为0.56%。LA-Zein-MC纳米粒子形貌光滑，LA被包埋在纳米粒子内部，该纳米粒子具有较高的NaCl稳定性和热稳定性。此外，LA实现了可控缓释。     

无卤阻燃聚酰胺6／有机粘土纳米复合材料的制备和性能

无卤阻燃聚酰胺6／有机粘土（PA6／OMT）纳米复合材料用氢氧化镁（MH）和红磷（RP）作为阻燃剂、有机粘土（OMT）作为增效剂,通过熔融共混技术制备。形态学用XRD和TME表征。有机粘土对阻燃PA6机械性能和可燃性的影响进行了试验。结果表明,纳米复合材料的机械和阻燃性能比阻燃PA6高,OMT、MH和RP之间具有增效效应。     

EPDM/纳米CaCO3预混料动态力学性能及其对聚丙烯基三元复合材料韧性的影响

采用熔融法分别制备了三元乙丙橡胶(EPDM) /纳米碳酸钙（CaCO3）二元预混料及其与聚丙烯（PP）共混的三元复合材料。利用动态力学分析仪研究了纳米CaCO3含量和共混时间对EPDM /纳米CaCO3二元预混料的动态力学性能的影响,利用扫描电子显微镜分析了分散相纳米CaCO3和EPDM在PP基体中的形态。结果表明,常温下,纳米CaCO3含量为70 %（质量分数,下同）、共混时间为15 min时,EPDM/纳米CaCO3二元预混料的储能模量、损耗模量和损耗角正切达到最高值;纳米CaCO3与EPDM组成的二元共混物分散于PP基体中,通过纳米CaCO3团聚体及EPDM协同变形、界面脱黏成纤及诱导剪切带的形成耗散外界作用能,显著提高了PP/EPDM/纳米CaCO3三元复合材料的冲击强度。     

环氧树脂/二烷基次膦酸铝阻燃体系的制备和性能

着重研究了环氧树脂/二乙基次膦酸铝（EP/OP930）阻燃材料的阻燃性能、热分解性能和力学性能。结果表明,OP930的含量仅需15 %（质量分数,下同）就可以使EP/OP930体系的极限氧指数达到29.8 %,垂直燃烧实验达到UL 94 V-0级标准;此外,EP/OP930体系的综合性能良好,不同OP930含量的阻燃材料的力学性能、热稳定性能与原材料相比变化不大。     

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.     

Carbon nanotubes coated with phosphorus-nitrogen flame retardant and its application in epoxy thermosets

ABSTRACT

Carbon nanotubes coated with phosphorus-nitrogen flame retardant (PDAP-CNTs) were produced. The compositions and structures of PDAP-CNTs were systematically characterized, and the flame retardancy of PDAP-CNTs/EP composites were also tested. The results indicated that PDAP-CNTs demonstrated excellent flame retardancy performance on the flame-retardant EP composites (FR-EP), incorporation of 5.0wt% PDAP-CNTs improved the LOI values of EP from 26.0% to 31.8% and reached UL-94 V-0 classification. The analysis of flame-retardant mechanism indicating the flame-retardant ability of PDAP-CNTs was ascribed to the synergism of the phosphorus-nitrogen containing coating layer (PDAP) and CNTs.     

Effect of gas-condensed phase synergistic system of 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide and polydopamine on flame retardancy of epoxy resin

Polydopamine (PDA) was prepared by using dopamine which has good charring ability. The PDA was used as an environmentally friendly flame retardant and combined with 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) to improve the flame retardancy of epoxy (EP) resin. The flame retardancy and thermal stability of EP composites were researched by UL-94 vertical burning, limiting oxygen index (LOI), cone calorimetry tests, and thermal gravimetric analyzer. Adding DOPO alone requires 6% to make EP obtain the UL-94 V0. If DOPO and PDA are combined, only 4% is needed to make EP obtain the UL-94 V0, which suggests that there is good synergistic effect between them. Moreover, the peak of heat release rate of EP/DOPO/PDA composites is less than that of EP/DOPO composites. The reactions among EP, DOPO, and PDA reduce the release of combustible gases at the early stage of degradation; at the same time, DOPO volatilize to the gas phase, quench the free radicals, and the combustion can be stopped. In addition, due to the decrease of the amount of PDA/DOPO, the EP composite can get a higher glass transition temperature, but due to the aggregation of PDA in EP, the tensile property of EP composite decreases.     

Flame retardant performance of a carbon source containing DOPO derivative in PET and epoxy

The combination of gas‐phase and condensed‐phase action will contribute to high quality flame retardant. A novel 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO)‐based flame retardant (DOPO‐DOPC), which contains carbon source was synthesized in favor of conducting the effect of gas‐phase as well as promoting the char formation in condensed‐phase. The chemical structure of DOPO‐DOPC was characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). DOPO–DOPC was used as an additive in poly(ethylene terephthalate) (PET) and epoxy resin (EP). The flame retardancy of PET/DOPO‐DOPC and EP/DOPO‐DOPC composites were studied by limiting oxygen index (LOI) and UL‐94 test. The results showed that the incorporation of DOPO–DOPC into PET or EP could obviously improve their flame retardancy. The LOI values of modified PET or EP, which contained 10 wt % DOPO‐DOPC reached 42.8 and 31.7%, respectively. The thermogravimetric analysis (TGA) results revealed that DOPO–DOPC enhanced the formation of char residues. The Laser Raman spectroscopy (LRS) was used to investigate the carbon structure of thermal oxidation residues. Because of the combination of the gas phase flame retardant effect of DOPO moiety and the promoting formation of char residues in condensed phase, the PET and EP composites exhibited significant improvement toward flame retardancy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44639.     

Preparation of novel biomass humate flame retardants and their flame retardancy in epoxy resin

Humic acid (HA), a biomass material with plentiful oxygen-containing functional groups, showed huge potential to be considered as a promising charring agent in flame retardancy. In this study, this HA was modified with four different metal ions like Fe²⁺, Mn²⁺, Al³⁺, and Cu²⁺ and finally, introduced into the epoxy resin (EP) to enhance the flame retardancy of the EP and the dispersion of these flame retardants into the EP matrix. When 10 wt% of HA-Fe and HA-Mn were incorporated into EP matrix, the limiting oxygen index (LOI) was increased from 21.2% for EP to 26.6 and 25.3% for the EP composites and the peak heat release rate (pHRR) was reduced by 36 and 35.5%, respectively. Such a significant improvement in flame retardancy was attributed to the catalytic charring of HA in the presence of metal ions, which ultimately increased the residual char formation and produced compact char layers during the combustion process to retard the transfer of heat and combustible gases between the EP composites and the flame zone. Finally, this kind of application provided a feasible way for the development of an environmentally friendly flame retardant with high efficiency, which improved the fire safety of EP matrix.     

Superior thermal stability and smoke suppression of epoxy resin composites with graphene/LDH phosphorus-rich hybrids

In this article, graphene/LDH phosphorus-rich triple hybrid was prepared by a mild method and used to effectively improve the thermal stability and smoke suppression of epoxy resin (EP). The graphene was firstly reacted with hexamethylenediamine (HA) and followed by the treatment with the layered double hydroxide (LDH) and NaH₂PO₄ solutions. Compared to the unmodified graphene, the initial decomposition temperature of the triple hybrids increases significantly from 168.6 to 292.5°C. The residual carbon content is greatly improved and the residual mass is up to 84.1%. Elemental analysis reveals the content of phosphorus in EP composites is as high as 10 wt%. In flame retardancy tests, the peak heat release rate of the EP composite with 5 wt% graphene/LDH phosphorus-rich hybrids decreases to 786.15 KW/m², 41.19% drastic reduction compared to that of EP. These results indicate that the triple functionalization process effectively expands the interval distribution of heat release and makes the heat release process more gradual and spread flames smaller. The smoke production rate and total smoke production rate of EP composite with 5 wt% graphene/LDH phosphorus-rich hybrids are 0.32 m²/s and 40.91 m², which are significantly reduced by 65.22 and 57.83%, respectively. This gentle and efficient process provides a new approach to multi-functional design to improve the thermal stability and smoke suppression of resin-based composites.     

三氧化二锑/水滑石协效阻燃ABS应用研究

为克服阻燃剂在聚合物基体中的分散性和相容性较差等问题,采用三氧化二锑(AT)粉末对水滑石(LDH)进行改性,并对改性LDH进行表征。将AT/LDH和四溴双酚A(TBBPA)掺入ABS制备复合材料,并研究不同配方对复合材料的阻燃性能和力学性能的影响。结果表明:AT的加入不改变LDH的层状结构。AT/LDH在高温下表现较好的热稳定性。改性LDH克服阻燃剂团聚的趋势。当m(AT)∶m(TBBPA)为1∶6,m(AT)∶m(LDH)为15%,ABS复合材料的极限氧指数(LOI)达到29.5%,垂直燃烧测试达到V-0级,而弯曲强度和拉伸强度与纯ABS相比分别下降36.38%和20.40%。     

Zirconium-Embedded Polyhedral Oligomeric Silsesquioxane Containing Phosphaphenanthrene-Substituent Group Used as Flame Retardants for Epoxy Resin Composites

A zirconium hybrid polyhedral oligomeric silsesquioxane derivative (Zr–POSS–bisDOPO) is synthesized by the corner-capping and Kabachnik–Fields reactions. It is characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR), and then used as a flame retardant in diglycidyl ether of bisphenol A (DGEBA) to endow epoxy resin (EP) with flame retardancy. The flame retardancy, thermal stability, and mechanical properties of the cured EP/Zr–POSS–bisDOPO composites are investigated. The results show that when Zr–POSS–bisDOPO is added by 5–7 wt%, the EP/Zr–POSS–bisDOPO composites pass the UL-94 V-0 rating test. In addition, they have a better flame-retardant effect than pure EP. The combination of Zr atom embedded in the Si O cubic cage and the two phosphaphenanthrene substituent groups in one corner of cubic cage is expected to realize the Zr/Si/P ternary intramolecular hybrid synergistic effect and achieve the possibility of dispersing metal–POSS cages at a sub-micrometer-scale level into polymer matrix. It also proves that Zr–POSS–bisDOPO produces phosphorus-containing free radicals and terminates the chain reactions in gas phase. Meanwhile the Si O Si and Zr O units are retained in the solid phase, which promote the char formation and enhance the flame retardancy. This kind of Zr-doped POSS will be helpful for developing the new metal–POSS hybrid flame-retardant and polymer composites.     

纳米Al_2O_3对含磷环氧树脂体系的性能影响

研究了以纳米Al_2O_3作为协同阻燃剂,对EP/DOPO和EP/HPCTP树脂固化物阻燃性能的影响。通过热重分析测试(TGA)、动态热机械分析测试(DMA)、氧指数测定(LOI)及垂直燃烧测试(UL-94)重点探讨了树脂固化物的耐热及阻燃性能。测试结果表明,含磷阻燃剂有助于提高环氧树脂固化物的阻燃性能,但会降低其玻璃化转变温度(Tg)。随着纳米Al_2O_3的加入,残炭率(800℃)、极限氧指数(LOI)得到进一步的提高,并且能够在一定程度上提升树脂固化物的玻璃化转变温度(Tg)和初始热裂解温度(T5%)。