溶液共混法制备聚氨酯／碳纳米管复合材料及其性能

 通过强酸处理方法对碳纳米管进行改性处理并对其结构和分散稳定性进行分析。采用溶液共混法制备了聚氨 酯/碳纳米管复合材料,利用FTIR对其结构进行了分析,探讨了碳纳米管对复合材料力学性能、热稳定性能以及弹 性回复率的影响。结果表明,碳纳米管经酸处理后添加了羧酸活性基团,提高了其在溶剂中的分散性|在复合材料 中,碳纳米管以较强氢键与大分子连接,复合材料的力学性能和热稳定性能都有所提高,而弹性回复率没有受到很 大影响。     

制备方法对聚氨酯/碳纳米管复合材料性能的影响

对碳纳米管(CNTs)进行酸改性,采用溶液共混法和原位聚合法制备了聚氨酯(PU)/CNTs复合材料,考察了CNTs对复合材料力学性能、热稳定性能和弹性回复率的影响.结果表明,与PU相比,用该2种方法制备的PU/CNTs复合材料的力学性能和热稳定性能都有所提高,但用原位聚合法提高的程度较大,而制备方法对复合材料的弹性回复性影响不大.     

原位聚合法制备热塑性聚氨酯/多壁碳纳米管复合材料及其性能研究

采用原位聚合法制备了热塑性聚氨酯/多壁碳纳米管(TPU/MWNT)复合材料,利用热重分析(TGA)、体积电阻率测试、维卡软化点测试、力学性能测试,研究了多壁碳纳米管(MWNT)质量分数对复合材料热稳定性、导电性以及力学性能的影响。结果表明,经酸化处理的MWNT可以显著提高复合材料的热稳定性和力学性能,质量分数为0.8%的TPU/MWNT复合材料具有最优异的热稳定性和力学性能。同时,一定含量的MWNT能够搭建三维网络结构,使材料的导电性和耐热性也得到了显著提高。     

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。     

聚氨酯/碳纳米管复合材料的制备及其性能研究

通过强碱球磨方法对多壁碳纳米管(MWCNTs)进行了改性处理,并对其化学结构和微观形态进行了分析.采用溶液共混法制备了聚氨酯(PUR)/MWCNTs复合材料.利用扫描电子显微镜、傅立叶变换红外光谱仪对其进行了表征.探讨了MWCNTs对PUR/MWCNTs复合材料力学性能、热稳定性以及电导率的影响.结果表明,MWCNTs...     

硅橡胶/多壁碳纳米管复合材料的结构与性能研究

研究了硅橡胶/多壁碳纳米管复合材料的形态结构和物理机械性能。利用扫描电子显微镜观测了复合材料中多壁碳纳米管的分散情况,并测试分析了复合材料的力学性能、热性能、动态力学性能。结果表明,多壁碳纳米管能够良好地分散在硅橡胶基体中,随着多壁碳纳米管用量的增加,硅橡胶/多壁碳纳米管复合材料热稳定性明显提高,且有效地提高了硅橡胶的物理机械性能。硅橡胶/多壁碳纳米管复合材料中形成了碳纳米管的某种形式网络结构,网络结构的打破与重建导致了储能模量的非线性下降。     

共混型石墨烯/碳纳米管/SMTPU复合材料的制备与性能研究

为改善形状记忆热塑性聚氨酯(SMTPU)的力学和形状记忆性能,通过熔融共混技术制备了氧化石墨烯/多壁碳纳米管复合填充改性的SMTPU复合材料,其中,氧化石墨烯首先用乙二胺进行接枝改性,多壁碳纳米管用硫酸/硝酸混合酸进行了处理。进一步研究了上述填料的加入对所得复合材料的力学性能、熔体流动速率及形状记忆性能的影响。结果表明,填料含量对复合材料的力学和形状记忆性能有明显的影响。固定氧化石墨烯与多壁碳纳米管的质量比为1,当它们在复合材料中的质量分数为0.5%时,复合材料的拉伸强度较纯SMTPU提高了25.2%。随着填料含量的增加,复合材料的熔体流动速率逐渐降低。形状记忆性能研究表明,加入氧化石墨烯/多壁碳纳米管使得复合材料的形状固定率先上升后下降,而且在氧化石墨烯/多壁碳纳米管的质量分数为0.5%时,复合材料形状固定率最大,较纯SMTPU提高了26.4%;形状回复率则随填料含量的增加逐渐上升,且回复温度越高,形状回复率越好。     

聚合物/碳纳米管的研究进展

碳纳米管具有独特的结构，优异的力学性能、热稳定性与导电性能，与聚合物并用可开发出多种新型复合材料，评述利用直接混合法、原位聚合法与超声波处理法制备聚合物／碳纳米管材料，并讨论该复合材料的力学性能，光电性能与磨擦学性能。     

碳纳米管增韧氮化硅陶瓷复合材料的探讨

采用热压烧结法制备了Si3N4/碳纳米管复合材料,研究了碳纳米管的含量及不同烧结温度对该材料的力学性能的影响, 主要探讨了该复合材料的强韧化机理.     

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%。     

Carbon Nanotube Reinforced Alumina-Based Ceramics with Novel Mechanical, Electrical, and Thermal Properties

The extraordinary mechanical, thermal, and electrical properties of single-wall carbon nanotubes (SWCNT) have prompted the development of advanced engineering materials with improved properties through the incorporation of carbon nanotubes in selected matrices. Dense SWCNT reinforced alumina nanocomposites have been fabricated by novel spark-plasma-sintering (SPS) technique. SWCNT were also successfully used to convert insulating nanoceramics to metallically conductive composites. Additionally, novel anisotropic thermal properties have been observed in the carbon nanotube composites. Such multifunctional carbon nanotube/ceramic composites with improved mechanical and electrical properties along with anisotropic thermal properties are envisaged for a wide range of applications.     

碳纳米管/橡胶复合材料的制备与性能研究进展

介绍了碳纳米管/橡胶复合材料的直接共混、溶液共混、乳液共混、熔融共混、原位聚合制备工艺,综述了碳纳米管/橡胶复合材料的加工性能、力学性能和电性能,指出今后的发展方向是开发新的碳纳米管制备技术、探索碳纳米管的纯化和改性方法、研究碳纳米管/橡胶复合材料的制备技术及其结构与性能的关系.     

Sensing behaviors of polymer/carbon nanotubes composites prepared in reversed microemulsion polymerization

Polystyrene/carbon nanotubes composites were readily prepared by reversed microemulsion polymerization. Compared with the composites prepared by solution mixing, the uniform dispersion of carbon nanotubes in polymer matrix could be obtained more easily and the thermal and electrical properties of the as‐prepared composites were also enhanced. The as‐prepared composites were deposited onto a microelectrode array to fabricate a vapor sensor. The response for different organic vapors was evaluated by monitoring the change in the resistance of the composites upon exposure to various gases. The change in resistance was of the order of about 10³ for the composites prepared by reversed microemulsion polymerization. The chemical sensors based on the composites prepared by reversed microemulsion polymerization presented excellent reproducibility and reversibility in response. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Electrical and mechanical properties of polyimide-carbon nanotubes composites fabricated by in situ polymerization

Polyimide (PI)-carbon nanotubes composites were fabricated by in situ polymerization using multi wall carbon nanotubes (MWNT) as fillers. It suggested that in situ polymerization is an ideal technique to make a perfect dispersion of carbon nanotubes into matrixes. Besides it, the pre-treatment of carbon nanotubes in solvent to make the networks untied enough and to let solvent percolated into the networks is very important for forming uniform entanglements between carbon nanotubes and polymer molecular chains. The results imply that the percolation threshold for the electric conductivity of the resultant PI-MWNT composites was ca. 0.15 vol%. The electrical conductivity has been increased by more than 11 orders of magnitude to 10⁻⁴ S/cm at the percolation threshold. The mechanical properties of the polyimide composite were not improved significantly by addition of carbon nanotubes.     

Synthesis and characterization of multiwalled carbon nanotube/polyurethane composites via surface modification multiwalled carbon nanotubes using silane coupling agent

Well‐dispersed multiwalled carbon nanotubes/polyurethane (MWCNTs/PU) composites were synthesized in situ polymerization based on treating MWCNTs with nitric acid and silane coupling agent. The morphology and degree of dispersion of the MWCNTs were studied using a high resolution transmission electron microscopy (HR‐TEM) and X‐ray powder diffraction (XRD). The result showed that MWCNTs could be dispersed still in the PU matrix well with the addition of 2 wt% MWCNTs. The thermal and mechanical properties of the composites were characterized by dynamic mechanical thermal analysis, thermogravimetric analysis, tensile, and impact testing. The result suggested that the glass transition temperature (T_g) of composites increased greatly with increasing MWCNTs content slightly, and the MWCNTs is also helpful to improve mechanical properties of composites. Furthermore, the composites have an excellent mechanical property with the addition of 0.5 wt% MWCNTs. The electrical property testing indicates that the MWCNTs can improve evidently the electrical properties of composites when adding 1 wt% MWCNTs to the PU matrix. The volume resistivity of composites reaches to an equilibrium value. POLYM. COMPOS., 33:1866–1873, 2012. © 2012 Society of Plastics Engineers     

己二胺接枝单壁碳纳米管用于环氧复合材料

利用碳二亚胺活化碳纳米管上羧基的方法将1,6-己二胺接枝到单壁碳纳米管上。通过酸碱滴定确定了碳纳米管壁上羧基的含量,并对产物进行了红外和热重分析。将改性后的碳纳米管用于环氧复合材料,测试了材料的力学性能和电性能,并通过扫描电镜观察了断裂面的形貌。结果表明,羧基化碳纳米管上35%左右的羧基发生了酰胺化反应,碳纳米管上平均每100个碳原子接枝上2个己二胺分子链。经己二胺接枝改性后的碳纳米管在环氧树脂中的分散质量和界面粘合均得以明显改善。SWNT质量分数为1%时,复合材料的拉伸强度、弹性模量和断裂伸长率分别为(89.13±3.97)MPa,(2.03±0.18)GPa,(2.95±0.29)%,较纯环氧树脂分别提升了108%,28%和8%;电导率由纯环氧树脂的1.45×10-15 S/cm提高到7.36×10-4 S/cm。复合材料的性能有了很大的提高。     

Effect of functionalization on the thermo-mechanical and electrical behavior of multi-wall carbon nanotube/epoxy composites

The effect of the functionalization of multi-wall carbon nanotubes (MWCNTs) on the structure, the mechanical and electrical properties of composites was investigated. Samples based on epoxy resin with different weight percentage of MWCNTs or COOH-functionalized carbon nanotubes (MWCNT–COOH) were prepared and characterized. Dynamic-mechanical thermal analysis shows that the storage modulus increases with the addition of MWCNTs, whereas a constant value or even a weak reduction was observed for functionalized nanotubes. Two phases were suggested in the composites with MWCNT–COOH, both by dynamic-mechanical properties and by water transport. Chemical functionalization of MWCNTs increases the compatibility with the epoxy matrix due to the formation of an interface with stronger interconnections. This, in turn, causes a significant decrease in the electrical conductivity of this type of composite with respect to the untreated MWCNTs which can be explained in terms of tunnelling resistance between interacting nanotubes.     

碳纳米管/橡胶复合材料的研究进展

介绍了碳纳米管(C NTs)的预处理方式,主要有纯化处理和表面改性2种方式,概述了CNTs/橡胶复合材料的制备方法,包括机械混炼法、溶液共混法和喷雾干燥法,以及复合材料的物理机械性能、电学性能、热学性能等性能,并根据复合材料的性能缺陷提出今后的研究方向.     

Study on physical properties of multiwalled carbon nanotube/poly(phenylene sulfide) composites

The multiwalled carbon nanotubes were directly compounded with poly(phenylene sulfide) (PPS) via melt mixing. The morphology and physical properties, including viscoelasticity, electrical conductivity, and thermal and mechanical properties, of the obtained composites were investigated. The results show that the purified nanotubes can be fully dispersed in the PPS matrix especially at low loading levels because of their good affinity. The composites hence present relative low rheological and electrical percolation thresholds. The presence of nanotubes, on the one hand, shows good reinforcement effect because of the strong interfacial interactions with the PPS matrix, which is confirmed by the strain overshoot flow behavior, and, on the other hand, acts as a nucleation agent, promoting crystallization of the PPS matrix. Both contribute to evident improvement of tensile strength and dynamic mechanical properties of the composites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers