Mechanical properties carbon nanotube reinforcement

In addition to the mechanical properties, carbon nanotube-reinforced polymers have interesting electrical properties, in particular, their electrical conductivity... 

Biercuk MJ, Llaguno MC, Radosavljevic M, Hyun JK, Johnson AT (2002). Morphological and mechanical properties of carbon-nanotube-reinforced semicrystalline and amorphous polymer composites. Appl. Phys. Lett. 80 2767-2769. 

Concerning carbon nanotube-reinforced silicon nitride matrices, only a few reports have so far been published [19]. In this case, hot isostatic pressing has been used for composite processing. The carbon nanotubes remained in the microstructure only under low pressures (2 MPa) they connect the silicon nitride grains and produce a 15-37% improvement of the mechanical properties as compared with other carbon-filled samples (Fig. 19.11). Increase of pressure... 

Due to their unique mechanical and electronic properties carbon nanotubes (CNT) are promising for use as reinforcing elements in polymer matrixes [1, 2]. The main problems are creation of strong cohesion of CNT with a polymer matrix and uniform distribution of CNT in matrix [3], The goals of this work were development of PTFE-MWNT nanocomposite material with high mechanical characteristics and investigation of influence of MWNT surface groups on mechanical and electronic parameters of the composite material. 

Ji JY et al (2009) Significant improvement of mechanical properties observed in highly aligned carbon-nanotube-reinforced nanolibers. J Phys Chem C 113(12) 4779 785... 

F. Ye, L. Liu, Y. Wang, Y. Zhou, B. Peng, and Q. Meng, Preparation and mechanical properties of carbon nanotube reinforced barium aluminosilicate glass-ceramic composites. Script. Mater., 55, 91 M (2006). 

Della, C.N., Dongwei, S. Mechanical properties of carbon nanotubes reinforced ultra high molecular weight polyethylene. Solid State Phenom. 136, 45-49 (2008)... 

AyatoUahi, M. R., Shadlou, S., and Shokrieh, M. M., Multiscale modeling for mechanical properties of carbon nanotube reinforced nanocomposites subjected to different types of loading. Composite Structures, 93, 2250-2259 (2011). 

The addition of nanoparticles to synthetic mbber resulting in enhancement in thermal, stiffness and resistance to fracture is one of the most important phenomena in material science technology. Thermal and mechanical properties of clays mul-tiwalled carbon nanotubes reinforced ethylene vinyl acetate (EVA) prepared through melt blending showed synergistic effect in properties [86]. Malas et al. reported (SBR/BR)/expanded graphite (EG) and black carbon (CB) nanocomposites by melt blending, this study demonstrated that the presence of EG improvement thermo-mechanical properties and the presence of CB are a factor important to... 

A reduction of the required energy could be reached by the incorporation of conductive fillers such as heat conductive ceramics, carbon black and carbon nanotubes [103-105] as these materials allowed a better heat distribution between the heat source and the shape-memory devices. At the same time the incorporation of particles influenced the mechanical properties increased stiffness and recoverable strain levels could be reached by the incorporation of microscale particles [106, 107], while the usage of nanoscale particles enhanced stiffness and recoverable strain levels even more [108, 109]. When nanoscale particles are used to improve the photothermal effect and to enhance the mechanical properties, the molecular structure of the particles has to be considered. An inconsistent behavior in mechanical properties was observed by the reinforcement of polyesterurethanes with carbon nanotubes or carbon black or silicon carbide of similar size [3, 110]. While carbon black reinforced materials showed limited Ri around 25-30%, in carbon-nanotube reinforced polymers shape-recovery stresses increased and R s of almost 100% could be determined [110]. A synergism between the anisotropic carbon nanotubes and the crystallizing polyurethane switching segments was proposed as a possible... 

Mathur, R. B. Pande, S. Singh, B. P. Dhami, T. L. Electrical and mechanical properties of multi-walled carbon nanotubes reinforced pmma and ps composites. Polym. Comps. 2008, 29, 717-727. 

Xiao, K. Q. Zhang, L. C. Zarudi, I. Mechanical and rheological properties of carbon nanotube reinforced polyethylene composites. Comp. Sci. Technol. 2007, 67, 177-182. 

On the other hand, CNTs possess one of the highest thermal conductivities, which can be exploited to fabricate thermally conductive nauocomposites [8,9]. This chapter wiU focus on the applications of CNTs as discontinuous reinforcement for polymer matrices, which includes fabrication methods, morphologies and mechanical properties of the carbon nanotubes reinforced polymer nanocomposites. 

To summarize, the mechanical properties of carbon nanotube reinforced polymer composites mainly depend on the following factors ... 

Liu T X, Phang I Y, Shen L, Chow S Y and Zhang W D (2004) Morphology and mechanical properties of multiwalled carbon nanotubes reinforced nylon-6 composites, Macromolecules 37 7214-7222. 

Carbon nanotubes are long cylinders of covalently bonded carbon atoms and have a diameter from a few angstroms to several tens of nanometers. Carbon nanotubes have exceptional mechanical properties [47-50], and extensive research work has been carried out on carbon nanotube-reinforced polymer composites [46-52]. However, weak interfacial bonding between carbon nanotubes and polymers leads to poor stress transfer, and this has limited the full realization of carbon nanotubes as reinforcements for polymers. Therefore, chemical functionalization of carbon nanotubes has been conducted. 

Zeng, H.L. Gao, C. Wang, Y.P. Watts, P.C.P. Kong, H. Cui, X.W. Yan, D.Y. (2006a). In situ polymerization approach to multiwalled carbon nanotubes-reinforced nylon 1010 composites Mechanical properties and aystaUization behavior. Polymer, 47, 113-122. 

Abu-Abdeen M (2012) Investigation of the rheological, dynamic mechanical, and tensile properties of single-walled carbon nanotubes reinforced poly(vinyl chloride). J Appl Polym Sci 124(4) 3192-3199... 

For CNTs not well bonded to polymers, Jiang et al. [137] established a cohesive law for carbon nanotube/polymer interfaces. The cohesive law and its properties (e.g., cohesive strength, cohesive energy) are obtained directly from the Lennard-Jones potential from the van der Waals interactions. Such a cohesive law is incorporated in the micromechanics model to study the mechanical behavior of carbon nanotube-reinforced composite materials. CNTs indeed improve the mechanical behavior of composite at the small strain. However, such improvement disappears at relatively large strain beeause the eompletely debonded nanotubes behave like voids in the matrix and may even weaken the composite. The increase of interface adhesion between CNTs and polymer matrix may significantly improve the composite behavior at the large strain [138]. 

The exceptional mechanical and physical properties of carbon nanotubes along with low density make this new form of carbon an excellent candidate for composite reinforcement. The understanding thermo-mechanical properties of nanotube-based composite require knowledge of the elastic, fracture, and interface interaction of nanotube. 

Another method to improve the mechanical properties such as interfacial strength is to add nanosized carbon fiber-reinforced particles into the composite [18-20]. A strong influence of a uniform dispersion of the small-sized fibers or partides on the composite properties of advanced nanocomposites, such as carbon nanotube-reinforced composites was also reported [21-24]. However, few papers mention the enhancing method for improving the interfacial adhesion between fiber and matrix in a natural BF composite. 

The importance of promoting better knowledge in the field of polymer composites is demonstrated by the contents of this volume, which contains 18 Independent chapters. The first part of this volume deals with the topic of structure and properties of polymer nanocomposites. In Chapter 1, Schulte et al. review the state of the art of carbon nanotube-reinforced polymers. The opportunity to apply carbon nanotubes as a filler for polymers and the improvement of the mechanical and functional properties are discussed. The application of non-layered nanoparticles in polymer modification is described by M. Q. Zhang et al. in Chapter 2. A grafting polymerization technique is applied to inorganic nanoparticles, which helps to provide the composites with balanced performance. Chapter 3, authored... 

X.J. Xu, M.M. Thwe, C. Shearwood, K. Liao, Mechanical properties and interfacial characteristics of carbon-nanotube-reinforced epoxy thin films. Appl. Phys. Lett. 81(15), 2833-2835 (2002)... 

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