聚合物/碳纳米管导电复合材料研究进展

综述了聚合物/碳纳米管复合材料的制备方法及其电学性能的研究进展。评述了聚合物/碳纳米管复合材料常用的制备方法,包括溶液共混、熔融共混、原位聚合等,特别强调碳纳米管在聚合物基体中的分散;介绍了采用聚乙烯、环氧树脂等为基体的碳纳米管复合材料电学性能研究的两个方面:导电渗流行为和正温度系数效应;对聚合物/碳纳米管导电复合材料研究中存在的问题如工艺改进、机理解释等进行了讨论,并展望了这一类材料的发展前景。     

碳纳米管/聚合物复合吸波材料的研究进展

简要介绍了吸波材料研究的重要性,综述了碳纳米管/聚合物吸波材料的研究现状,主要包括碳纳米管/环氧树脂(ER)复合材料、碳纳米管/聚苯胺(PANI)复合材料以及碳纳米管/聚氯乙烯(PVC)复合材料的制备方法和吸波性能;并展望了碳纳米管/聚合物复合材料在航天工业领域的发展方向.     

环氧树脂/碳纳米管复合材料的性能研究

采用溶液混合法制备了环氧树脂/碳纳米管复合材料,探讨了碳纳米管的含量对复合材料拉伸和导电性能的影响。结果表明:随着碳纳米管含量的增加,复合材料的拉伸强度、杨氏模量和断裂伸长率均先提高后降低;当其质量分数为0.6%时,复合材料拉伸性能达到最优值且比纯环氧树脂分别提高了82.5%,40.2%和43.8%。复合材料的电导率呈现典型的渗阈行为,当碳纳米管的质量分数为1.8%时,复合材料电导率为1.31×10-5S/m,达到了半导体级别。     

碳纳米管/橡胶复合材料的制备方法及性能研究现状和进展

介绍近年来碳纳米管（CNTs>）改性的方法,包括共价键修饰和非共价键修饰。概述CNTs/橡胶复合材料的制备方法,包括机械共混法、熔融共混法、溶液共混法、喷雾干燥法、胶乳共混法、淤浆共混法,分别指出这些方法的优势及存在的问题。从CNTs/橡胶复合材料的力学性能、导热性能和导电性能着手,概述其研究进展,分析CNTs/橡胶复合材料领域存在的问题,展望CNTs/橡胶复合材料的制备及性能发展。     

碳纳米管/炭黑环氧树脂的制备与性能研究

使用CNTs和炭黑一同复合来改性善环氧树脂的性能,主要考察了固化剂用量、促进剂用量、碳纳米管/炭黑用量、超声时间和稀释剂用量对复合材料的导电性能和力学性能的影响。结果表明,加入环氧树脂2%~3%的碳纳米管/炭黑后能显著提升复合材料的导电性能和力学性能,通过多组分复合改性可以得到低成本高性能的环氧树脂材料。     

碳纳米管改性方法对其与聚氨酯的复合材料性能的影响

通过强酸回流、强碱球磨方法分别对碳纳米管进行了改性处理,采用溶液共混法制备了聚氨酯/碳纳米管复合材料。探讨了碳纳米管改性方法对复合材料的化学结构、微观形态、力学性能、热稳定性能以及导电性能的影响。结果表明,在聚氨酯基体中添加经化学改性处理的碳纳米管使复合材料的氢键增多,力学性能、热稳定性和导电性能都得到了提高。聚氨酯/强碱球磨处理碳纳米管复合材料中的氢键数目更多,综合性能也更优异,而且碳纳米管在聚氨酯基体中的分散更均匀。     

环氧树脂/碳纳米管纳米复合材料的制备与性能研究进展

综述了碳纳米管的基本性质和环氧树脂／碳纳米管纳米复合材料的制备方法及其力学性能、热性能、电性能、流变性能和摩擦性能。讨论了不同碳纳米管的制备方法、碳纳米管的类型、碳纳米管的表面处理等因素对复合材料性能的影响。指出了目前环氧树脂／碳纳米管复合材料研究中存在的问题，最后展望了这种高性能复合材料的发展前景。     

聚氨酯／碳纳米管复合材料的研究进展

近年来,利用碳纳米管制备聚氨酯复合材料引起人们的高度重视。本文对聚氨酯/碳纳米管复合材料的研究进展状况进行综述。概述了聚氨酯和碳纳米管的性质以及碳纳米管的改性处理方法;介绍了聚氨酯/碳纳米管复合材料的制备方法,包括物理共混法和原位聚合法;讨论了碳纳米管对复合材料力学性能、电学性能、光学性能以及其他性能的影响。结果表明,碳纳米管的加入使得复合材料在上述性能方面都有不同程度的改善。最后探讨了该研究领域存在的问题及今后可能的发展方向。     

微胶囊APP复配碳材料对EP阻燃和导电性能影响

以环氧树脂为壁材,聚磷酸铵(APP)为核,通过原位聚合的方式制备出微胶囊包覆聚磷酸铵(EAPP)。同时复配纳米碳材料(碳纳米管和石墨片),制备环氧树脂复合材料,研究了复合材料的阻燃和导电等性能。结果表明:经微胶囊包覆后的APP在环氧树脂基体中的分散性得到改善,复合材料的阻燃性能也得到提高。当100g环氧树脂添加10g EAPP及3g碳纳米材料时,复合材料的氧指数提高至28.6%,电导率提高至6.61×10-3S/cm,达到导电级别。     

碳纳米管/聚氨酯导电复合材料研究进展

聚氨酯广泛地应用在工业和日常生活中,但是其较差的导电性限制了它的进一步发展。碳纳米管作为一种优良的导电填料可以有效提高聚氨酯的导电性能。综述了碳纳米管/聚氨酯导电复合材料的制备方法、解释了导电机理以及应用方向。最后探讨了碳纳米管/聚氨酯导电复合材料在制备和应用中存在的问题以及今后的发展方向。     

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%。     

Effect of carbon nanotubes on the curing and thermomechanical behavior of epoxy/carbon nanotubes composites

The processing of carbon nanotube based nanocomposites is one of the fastest growing areas in materials research due to the potential of significantly changing material properties even at low carbon nanotube concentrations. The aim of our work is to study the curing and thermomechanical behavior of carbon nanotube/epoxy nanocomposites that are critical from an application standpoint. Multiwall carbon nanotubes–epoxy composites are prepared by solvent evaporation based on a commercially available epoxy system and functionalized multiwalled carbon nanotubes. Three weight ratio configurations are considered (0.1, 0.5, and 1.0 wt%) and compared to both the neat epoxy to investigate the nano‐enrichment effect. We focus here on the modification of the curing behavior of the epoxy polymer in the presence of carbon nanotubes. It has been observed that introducing the multiwall carbon nanotubes delays the polymerization process as revealed by the modification of the activation energy obtained by differential scanning calorimetry. The viscoelastic response of the nanocomposites was studied from the measurements of storage modulus and the loss factor using dynamic mechanical analysis to evaluate the effect of the interface in each matrix/carbon nanotube system with changing matrix mobility. These measurements provide indications about the increase in the storage modulus of the composites, shift in the glass transition temperature due to the restriction of polymer chain movement by carbon nanotubes. POLYM. COMPOS., 35:441–449, 2014. © 2013 Society of Plastics Engineers     

碳纳米管在环氧树脂改性中的应用研究进展

阐述了碳纳米管(CNTs)在EP(环氧树脂)基复合材料中的应用情况,着重讨论了CNTs表面改性的原因及其对EP基复合材料性能(包括力学性能、热性能和电性能等)的影响,并介绍了国内外该类复合材料的研究成果。最后对CNTs/EP基复合材料的研究方向进行了展望。     

Processing-structure-multi-functional property relationship in carbon nanotube/epoxy composites

The novel properties of carbon nanotubes have generated scientific and technical interest in the development of nanotube-reinforced polymer composites. In order to utilize nanotubes in multi-functional material systems it is crucial to develop processing techniques that are amenable to scale-up for high volume, high rate production. In this research we investigate a scalable calendering approach for achieving dispersion of CVD-grown multi-walled carbon nanotubes through intense shear mixing. Electron microscopy was utilized to study the micro and nanoscale structure evolution during the manufacturing process and optimize the processing conditions for producing highly-dispersed nanocomposites. After processing protocols were established, nanotube/epoxy composites were processed with varying reinforcement fractions and the fracture toughness and electrical/thermal transport properties were evaluated. The as-processed nanocomposites exhibited significantly enhanced fracture toughness at low nanotube concentrations. The high aspect ratios of the carbon nanotubes in the as-processed composites enabled the formation of a conductive percolating network at concentrations below 0.1% by weight. The thermal conductivity increased linearly with nanotube concentration to a maximum increase of 60% at 5 wt.% carbon nanotubes.     

Effects of surface modification on rheological and mechanical properties of CNT/epoxy composites

Despite superior properties of carbon nanotubes (CNTs), physical properties of the CNT/epoxy composites are not improved significantly because interfacial bonding between the CNTs and the polymer matrix is weak. CNTs were treated by an acidic solution to remove impurities and modified subsequently by amine treatment or plasma oxidation to improve interfacial bonding and dispersion of nanotubes in the epoxy matrix. The functional groups on the surface of treated CNTs were investigated by X-ray photoelectron spectroscopy. The surface modified CNTs were embedded in the epoxy resin by ultra-sonication and the cured nanotube containing composites were characterized by field emission scanning electron microscopy. Rheological properties of nanotube containing epoxy resin and mechanical properties of the modified CNT/epoxy composites were improved because the modification of CNTs improved dispersion and interaction between the CNT and the epoxy resin.     

新型炭黑填充抗静电和导电聚丙烯复合材料

以炭黑为导电填料,在聚丙烯中加入适量的环氧树脂和玻璃纤维,制备了新型的抗静电和导电聚丙烯复合材料。测定了不同复合体系的渗滤阈值,用扫描电镜(SEM)对相形貌进行了观察,并研究了环氧树脂和玻璃纤维用量对体积电阻率的影响。SEM照片表明在新型复合材料中,炭黑优先分布在环氧树脂中,环氧树脂包覆在玻璃纤维表面,通过玻璃纤维间的搭接形成导电通路。这种独特的结构使该复合材料的渗滤阈值低于聚丙烯/炭黑和聚丙烯/环氧树脂/炭黑复合体系的渗滤阈值。玻璃纤维和环氧树脂含量分别需要达到约10%,复合材料才能具有抗静电和导电作用。     

Effects of nanotube modification on the dielectric behaviors and mechanical properties of multiwall carbon nanotubes/epoxy composites

Multiwall carbon nanotubes (MWNTs) were modified by three methods, namely, oxidizing the tubes and opening both ends, filling the tubes with Ag, and grafting the tubes with hexamethylene diamine. Modified MWNTs/epoxy composites were prepared by melt‐mixing epoxy resin with the tubes. Transmission electron microscope images showed that the modified MWNTs can be dispersed in the epoxy matrix homogeneously. The dielectric behaviors and mechanical properties of the composites were investigated. The dielectric and mechanical properties of the modified MWNTs/epoxy composites were considerably improved compared with those of the epoxy matrix. The tensile strengths of the Ag‐filled, opened, and grafted MWNTs composites at the same filler content of 1.1 wt% were higher by ～30.5%, 35.6%, and 27.4%, respectively, than that of neat epoxy. The Izod notched impact strength of the grafted MWNTs/epoxy composite with filler content of 1.1 wt% was approximately four times higher than that of neat epoxy. A dielectric constant of ～150 of the composite with 1.1 wt% Ag‐filled nanotubes was observed in the low‐frequency range, which was ～40 times higher than that of the epoxy matrix. The proper modification of nanotubes provides a way to improve the properties of the polymer‐based composites. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

超声辐照制备聚醋酸乙烯酯/碳纳米管/炭黑导电复合材料

采用两步法制备了导电性聚醋酸乙烯酯/碳纳米管/炭黑复合材料。实验结果表明:超声辐照乳液聚合比常规搅拌能更有效地破坏CNTs的团聚和缠绕,实现其均匀分散。因而CNTs可作为"桥梁"连接导电炭黑,形成导电网络,增加复合材料中形成的导电通路数,增大载流子在导电粒子间的跃迁几率,提高聚醋酸乙烯酯/炭黑复合材料的导电率。当聚醋酸乙烯酯/炭黑复合材料中含有0.28%碳纳米管时,复合材料的电阻率从7.7×104Ω·cm降低到3.9×103Ω·cm,下降了19倍。     

Effect of functionalized carbon nanotubes on the thermal conductivity of epoxy composites

Direct functionalized carbon nanotubes (CNTs) were utilized to form the heat flow network for epoxy composites through covalent integration. A method of preparing a fully heat flow network between benzenetricarboxylic acid grafted multi-walled carbon nanotubes (BTC-MWCNTs) and epoxy matrix is described. A Friedel-Crafts modification was used to functionalize MWCNTs effectively and without damaging the MWCNT surface. Raman spectra, X-ray photoelectron spectra and thermogravimetric analysis reveal the characteristics of functionalized MWCNTs. The scanning electron microscope images of the fracture surfaces of the epoxy matrix showed BTC-MWCNTs exhibited higher solubility and compatibility than pristine-MWCNTs. The MWCNTs/epoxy composites were prepared by mixing BTC-MWCNTs and epoxy resin in tetrahydrofuran, followed by a cross-linking reaction with a curing agent. The BTC was grafted onto the MWCNTs, creating a rigid covalent bond between MWCNTs and epoxy resin and forming an effective network for heat flow. The effect of functionalized MWCNTs on the formation of the heat flow network and thermal conductivity was also investigated. The thermal conductivity of composites exhibits a significant improvement from 0.13 to 0.96 W/m K (an increase of 684%) with the addition of a small quantity (1-5 vol%) of BTC-MWCNTs.