碳纳米管改性氰酸酯树脂/碳纤维复合材料研究

采用多壁碳纳米管(MWNTs)为改性剂,对环氧树脂/双酚A型氰酸酯树脂体系进行增韧改性。以该改性体系制备了碳纳米管改性氰酸酯树脂/碳纤维复合材料。研究了MWNTs加入量对复合材料力学性能的影响,利用动态力学分析仪和扫描电子显微镜分别对该复合材料的耐热性及微观形貌进行了分析。结果表明,MWNTs的加入能明显地改善复合材料的耐热性和力学性能,当MWNTs的含量为1份和1.5份时,复合材料的层间剪切强度和弯曲强度分别提高约31%和23%。     

多壁碳纳米管改性氰酸酯树脂体系的研究

针对环氧树脂(DGEBA)／双酚A型氰酸酯树脂(BADCy)体系,采用多壁碳纳米管(MWNTs)对其增韧改性,制备了MWNTs/ DGEBA／BADCy复合材料。利用透射电子显微镜(TEM)观察MWNTs在树脂中的分散情况,研究了MWNTs的用量对复合材料性能的影响,借助凝胶时间和扫描电子显微镜(SEM)对碳纳米管增强氰酸酯树脂的机理进行初步的探讨。研究表明:当碳纳米管的质量分数为1％时,复合材料的力学性能达到最佳,弯曲强度和冲击强度分别提高约15％和8％。     

乙二胺修饰的碳纳米管对环氧树脂力学性能的影响

利用乙二胺对多壁碳纳米管(MWNTs)进行化学修饰,并制备碳纳米管/环氧树脂复合材料,研究了乙二胺修饰的碳纳米管对碳纳米管/环氧树脂复合材料力学性能的影响。实验表明,碳纳米管经乙二胺修饰后,改善了它在环氧树脂中的分散性,提高了环氧树脂复合材料的力学性能。氨基化碳纳米管用量达1.0%时,复合材料的冲击强度、断裂伸长率、拉伸强度和弯曲强度分别较纯环氧树脂提高200%、275%、48%和30%。     

超支化聚合物接枝纳米TiO_2/环氧树脂复合材料的制备与表征

利用偶联剂KH-550和超支化聚(胺-酯)(HBP)对纳米TiO2进行改性,并制备了纳米TiO2/环氧树脂(EP)复合材料。对复合材料的结构、力学性能、加工性能以及热性能进行了研究。研究结果表明,HBP接枝改性纳米TiO2(TiO2-g-HBP)的引入可明显提高复合材料的力学性能、热性能及加工性能;当w(TiO2-g-HBP)=1%时,复合材料的力学性能最好,其冲击强度和弯曲强度比纯EP分别提高了135.51%和22.98%;扫描电镜(SEM)结果显示,TiO2-g-HBP/EP复合材料由脆性断裂转变为韧性断裂。     

CE/EP/纳米SiC复合材料研究

采用纳米SiC和环氧树脂(EP)对双酚A型氰酸酯树脂(CE)进行改性。研究了不同含量的纳米SiC对CE/EP/纳米SiC复合体系反应性及CE/EP/纳米SiC复合材料力学性能的影响,采用透射电子显微镜表征了材料的微观形貌,利用差示扫描量热法研究了固化树脂的热性能。结果表明,纳米SiC对CE/EP/纳米SiC复合体系具有明显的催化作用,并且能使复合材料的冲击强度提高123.62%,弯曲强度提高140.29%,有效发挥其增强增韧作用,还能很好地保持复合材料的耐热性能。     

环氧树脂/纳米Si_3N_4复合材料的制备与性能研究

以纳米 Si_3N_4为填料制备了环氧树脂/纳米 Si_3N_4复合材料。通过透射电镜观察到,纳米粒子在有机基体中分散均匀。研究了纳米 Si_3N_4对复合材料性能的影响,结果表明,添加纳米 Si_3N_4使复合材料的力学性能增加,当改性环氧树脂/纳米 Si_3N_4为100/3(质量比,下同)时,复合材料的拉伸强度、弯曲强度、冲击强度提高幅度最大,分别提高了145%、241%、255%。此时,复合材料的击穿场强提高的幅度也达到最大,在直流电压和交流电压下,分别提高了249%、146%;但添加纳米 Si_3N_4使复合材料的介电常数和介质损耗值减小;热重分析表明,环氧树脂/纳米Si_3N_4复合材料耐热性能有明显提高。并用"核-壳过渡层"结构模型初步探讨了各项性能改善的原因。     

多壁碳纳米管在国产碳纤维增强环氧树脂复合材料中应用

研究了一种简易有效的多壁碳纳米管(MWNTs)分散入环氧树脂的方法,对树脂的工艺性进行试验研究;使用碳纤维复丝的力学性能来表征纤维/树脂界面性能和纤维强度转化效果,制备了含MWNTs的环氧树脂/碳纤维预浸料,并对使用此预浸料制备的复合材料单向板进行力学性能测试。结果表明,当MWNTs的用量为E–51的0.5%时,二者混合球磨8 h后配制的树脂溶液适用期大于24 h,黏度小于0.8 Pa·s,树脂浇铸体拉伸强度78 MPa,弯曲强度106 MPa,断裂伸长率4.3%;添加MWNTs之后纤维/树脂结合良好,复合材料单向板拉伸强度提升了7.2%,弯曲强度提升了9.73%,压缩强度提升了6.82%,层剪强度提升了11.54%。     

环氧树脂/炭纤维布/铝复合材料的力学性能和导热系数研究

使用硅烷偶联剂对纳米铝粉的表面进行了改性.采用共混和热压成型方法制备了环氧树脂/炭纤维布和环氧树脂/炭纤维布/铝粉复合材料,并研究了复合材料的力学性能和导热性能.结果表明,复合材料的弯曲强度和冲击强度随着炭纤维布用量的增加而显著增大;纳米铝粉的添加进一步提高了复合材料的弯曲强度和冲击强度.当炭纤维布用量从0层增加到4层...     

偶联剂表面处理对复合材料静态力学性能的影响

利用纳米SiO2对氰酸酯树脂(CE)进行增韧改性,采用冲击强度、弯曲强度测试及扫描电子显微镜等手段研究了纳米SiO2含量对纳米SiO2/CE复合材料静态力学性能的影响;在此基础上,分别选用小分子偶联剂KH-560和大分子偶联剂SEA-171对纳米SiO2进行表面处理,进一步研究了界面结构对纳米SiO2/CE复合材料静态力学性能的影响,初步探讨了其作用机理。结果表明,纳米SiO2(尤其是以大分子偶联剂处理后的纳米SiO2)的加入提高了复合材料的冲击强度和弯曲强度。当SiO2质量分数为3%时,复合材料的冲击强度、弯曲强度达到最大,增幅分别为61.9%,44.2%。     

一种基于氢氧化镁的环氧树脂固化剂的制备与表征

通过己二酸(AA)和二乙烯三胺(DETA)改性制得了一种氨基功能化氢氧化镁(DETA-AA-MH),并将其用作环氧树脂固化剂。采用FTIR、XRD、固体核磁、纳米粒径分析仪、SEM和TGA对DETA-AA-MH的化学结构、形貌以及热稳定性进行了表征,并通过FTIR和DSC分析得到环氧树脂(DGEBA)和DETA-AA-MH发生固化反应的最佳质量分数分别为84.03%和15.97%,热固化实验分析得到最佳反应条件为:预固化温度及时间(80℃/0.5 h)和后固化温度及时间(110℃/3 h)。LOI测试分析结果表明,DGEBA/DETA-AA-MH较DGEBA/DETA的LOI提高了10.15%。采用SEM和EDS对环氧树脂燃烧后的炭残留物进行分析,结果表明,在燃烧过程中DETA-AA-MH促进保护碳层的形成。机械性能测试表明,DGEBA/DETA-AA-MH(固化剂质量分数15.97%)与DGEBA/DETA(固化剂质量分数7.38%)对比发现其弯曲强度、弯曲模量和冲击强度分别提高了663.64%、49.92%、235.77%。     

Preparation and Properties of Nanocomposites Based on Hyperbranched Aliphatic Polyamide Functionalized Multiwalled Carbon Nanotubes and Bismaleimide Resin

Multiwalled carbon nanotubes (MWNTs) functionalized with hyperbranched aliphatic polyamide (HAP) were prepared by polycondensation using 3-(2-aminoethylamino)propanoic acid methyl ester as monomer. The effects of HAP functionalized MWNTs (MWNT-HAP) on the properties of bismaleimide (BMI) resin were investigated. Nanocomposites based on BMI resin and different content of MWNTs were prepared. The properties of nanocomposites were characterized by TGA, DMA, flexural and impact tests. Because of the magnification of functional groups and the higher interfacial interaction between MWNT-HAP and BMI resin, the improvement of the mechanical and thermal properties of MWNT-HAP/BMI nanocomposites was more remarkable than nanocomposites containing pristine MWNTs.     

碳纳米管／环氧树脂复合体系研究

采用熔融混合法,利用超声分散制备了碳纳米管／环氧树脂纳米复合材料。研究了羟基化碳纳米管的添加量对复合材料的反应活性的影响;同时测试了碳纳米管／环氧树脂纳米复合材料的弯曲性能和电性能,并利用透射电镜对碳纳米管在复合材料中的微观结构进行了表征。结果表明：碳纳米管使复合材料的反应活性有所提高;当碳纳米管含量为1％时,碳纳米管／环氧树脂复合材料的弯曲强度和弯曲模量分别由纯体系的143．32MPa和3563．76MPa提高到155．79MPa和3690．45MPa,碳纳米管在环氧树脂基体中呈单根分散。碳纳米管使复合材料的体积电阻率和表面电阻率下降2个数量级。     

多壁碳纳米管/环氧树脂纳米复合材料的固化动力学研究

采用熔融混合法向低粘度的环氧树脂中添加适量的多壁碳纳米管,制备新型纳米复合材料,并采用傅里叶变换红外光谱仪(FT-IR)测试转化率,采用差示扫描量热法(DSC)研究多壁碳纳米管/环氧树脂复合体系的固化动力学,并对纳米复合材料的力学性能进行研究。结果表明:多壁碳纳米管加入环氧树脂复合体系后,对固化反应有催化作用,固化反应速率增大,转化率提高,而复合体系的力学性能却有所下降,玻璃化转变温度变化不大。     

Property of intrinsic flame retardant epoxy resin cured by functional magnesium organic composite salt and diethylenetriamine

An efficient intrinsic flame retardants composite was prepared by curing epoxy resin with a functional magnesium organic composite salt (FMOCS, 0.685 ± 0.3 nm) and diethylenetriamine (DETA). Curing behavior, thermal and flame‐retardant properties of the cured epoxy resins were systematically investigated by infrared spectrum (FTIR), thermogravimetric analysis (TGA), vertical burning test (UL‐94) and limited oxygen index (LOI) measurement. It was found that flame retardancy and mechanical properties of the cured composite are significantly enhanced compared with DETA/EP. The LOI of the EP reached to 33%, which is much higher than the DETA/EP (19%) or its IFR composite (31%) in the optimal addition of ammonium polyphosphate (APP, 18.69 wt %), pentaerythritol (PER, 6.21 wt %) and FMOCS (3.50 wt %). Furthermore, the mechanical properties of the composite material measurement results to imply that it can enhance tensile strength (150%) and bending strength (88%) rather than DETA/EP, which were tested by impact testing machine and microcomputer control electron universal testing machines. Copyright © 2016 John Wiley & Sons, Ltd.     

Effects of functionalized MWNTs with GMA on the properties of PMMA nanocomposites

The acid modification of multiwall carbon nanotubes (MWNTs) was performed by an HNO₃/H₂SO₄ solution. The glycidyl methacrylate (GMA) undergoing an opening‐ring was grafted onto the surface of acid‐modified MWNTs. The surface properties of MWNTs were investigated by Fourier transform infrared spectrometer (FTIR), Raman spectra, transmission electron microscopy (TEM), X‐ray diffraction, and thermogravimeric analysis. Then the MWNTs/ poly(methyl methacrylate) (PMMA) nanocomposites were prepared by in situ polymerization. The tribological and dielectric properties of nanocomposites were studied. As a result, GMA was grafted on the surface of MWNTs. The tribological and dielectric properties of MWNTs/ PMMA nanocomposites were improved as the content of the surface‐modified MWNT increased. The marked improvement in tribological and dielectric properties were attributed to the good dispersion of MWNTs that were bonded with C?C on the surface that participated in the polymerization of MMA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and Application of a New Curing Agent for Epoxy Resin

A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal.     

Rheological behaviors and mechanical properties of graphite nanoplate/carbon nanotube-filled epoxy nanocomposites

In this work, the effect of multi-walled carbon nanotube (MWNT) contents on the rheological behaviors and mechanical interfacial properties of graphite nanoplate (GP)/epoxy nanocomposites was investigated. The results showed that the co-carbon fillers were homogeneously dispersed in the epoxy resins and MWNTs were intercalated into the GP layers. The storage modulus (G′) and loss modulus (G″) of the nanocomposites was increased with the addition of MWNTs. This result was accompanied by an increase in elastic properties of the nanocomposites, resulted from the higher aspect ratio of the MWNTs. And the mechanical properties of the nanocomposites were increased, as the MWNT content increased. It was noted that well dispersed MWNTs were strongly interacted with epoxy resins and worked as an effective reinforcement for the nanocomposites due to the flexible MWNTs compared with rigid GPs.     

Functionalizing carbon nanotubes by grafting cyclotriphosphazene derivative to improve both mechanical strength and flame retardancy

An intumescent flame‐retardant, hex(4‐carboxylphenoxy) cyclotriphosphazene (HCPCP) was synthesized and covalently grafted on to the surface of multiwalled carbon nanotubes (MWNTs) to obtain MWNT‐HCPCP. MWNT/epoxy resin (EP) and MWNT‐HCPCP/ EP nanocomposites were prepared via thermal curing. Transmission electron microscopy results showed that a core–shell structure with MWNTs as the hard core and HCPCP as the soft shell were formed after HCPCP (10 wt%) were attached to the MWNTs. The results of flammability tests showed an increased limited oxygen index value for MWNT‐HCPCP/EP nanocomposites. The mechanical properties including tensile strength and elongation were both dramatically improved due to the better dispersion of MWNT‐HCPCP in the EP matrix. The grafting of HCPCP can improve both the dispersion of nanotubes in polymer matrix and flame retardancy of the nanocomposites. POLYM. COMPOS., 35:2187–2193, 2014. © 2014 Society of Plastics Engineers     

多壁碳纳米管/聚碳酸酯复合材料的制备与性能

经硝酸氧化纯化的碳纳米管,在离子液体[Bmim]PF6存在下,溶液混合法制备了MWNTs/PC纳米复合薄膜。利用TEM、SEM对碳纳米管处理前后的形态结构、复合薄膜的微观结构进行了表征,考察了碳纳米管用量对MWNTs/PC复合材料的电学性质和力学性能的影响。结果表明,碳纳米管比较均匀地分散在PC基体中,在[Bmim]PF6作用下改善了碳纳米管与PC的相容性,提高了复合材料的力学性能。同时得出,复合材料的导电阈值出现在碳纳米管质量分数为1.0%～2.0%的范围内。     

Improvement of mechanical and electrical properties of epoxy resin with carbon nanofibers

In the present research, the reinforcement effect of vapor grown carbon nanofiber (VGCNF) was studied in relation to the mechanical properties and electrical conduction behavior of fabricated nanocomposites. Different weight fractions of nanofillers into epoxy resin, from 0.05 to 1 wt% and up to 2 wt% for mechanical and electrical properties were investigated. It was found that the optimum improvement in mechanical properties of nanocomposite is obtained at 0.25 wt% of carbon nanofibers. At this filler content, 23 % enhancement in tensile strength and 10 % in flexural strength have been observed. The degree of the VGCNF dispersion has been monitored by means of viscosity variation of the suspension during the sonication process to obtain the optimum sonication time. Finally, the quality of the dispersion for post-cured nanocomposites is characterized by fractured surfaces using the scanning electron microscopy. Agglomerates had a direct effect on the reduction of tensile and flexural strength of nanocomposites. The electrical conductivity was obtained by means of surface measuring method. The optimum amount of filler for the generation of a fine electrical conductivity was found to be around 0.5 wt% of VGCNF. After the threshold point, the electrical conductivity of nanocomposites was slightly raised in spite of adding more filler contents.