Interfacial Shear Strength of Mwnt / Epoxy Composites and Comparison with Molecular Dynamics Simulation

Carbon nanotubes (CNTs) have attracted much attention because of their unique structure and remarkable mechanical, electrical, thermal and chemical properties. In particular, it has been believed that CNTs are ideal fillers for polymers to enhance their mechanical properties. Numerous efforts have been devoted to the application of SWNTs and MWNTs to polymers for the last decade [1]. However, it has been revealed that mechanical properties of CNT-dispersed polymers are generally inferior to the theoretical values. It has been understood that the mechanical properties of CNT-dispersed polymer matrix composites are dominated mainly by dispersion, alignment, and interfacial shear strength (IFSS) between CNT and the polymer. In particular, weak IFSS between CNT and polymer is thought to be a critical problem [2]. From this perspective, many analytical studies have been conducted. However, it is not hard to anticipate that traditional methods are difficult to apply for measurements because of the extremely small size of CNTs, so direct comparison with analytical results and experimental results was not conducted. From this point of view, we proposed simple and easy method to evaluate the IFSS of CNT-dispersed thermoplastic polymer composites (so-called Nanopullout system [3]) for obtaining reasonable experimental results. In this study, the interfacial shear strengths of MWNT/ epoxy composites were evaluated using a nano-pullout method. Furthermore numerical simulations based on molecular dynamics (MD) were carried out. The experimental results were compared with the numerical results.