Role of structure and morphology in the elastic modulus of carbon nanotube composites

The nature of nanoscale reinforcements in the carbon nanotube composites indicates nanocomposite properties are heavily dependent on the micro/nano-structure and morphology. Macroscopic parameter-based properties estimation may lead to deviation as large as 30%. In this paper, a modified shear-lag model, combined with probability statistical theory and composites morphology, is established to investigate the elastic properties of single wall carbon nanotubes (SWNTs)-reinforced polymer composites. The computational results indicated that elastic modulus of nanocomposite was remarkably dependent on the micro/nano-structure, including diameter, length, and orientation of the dispersed SWNTs. Microstructure- dependent shape factor and orientation effect factor played a key role on achieving high-performance nanocomposites. Elastic modulus of nanocomposite with well-dispersed carbon nanotubes was more susceptible to the orientation. Similarly, nanocomposite modulus was more subject to the dispersion influence when SWNTs were well-aligned. The maximal modulus was located in the zone of small rope diameters and small orientation angles when adequate interfacial bonding was provided. The computational results were also compared with experimental outcome and demonstrated good consistence.