Molecular Dynamics Simulation of the Interfacial Characteristics of Functionalized Carbon Nanotube-Polyimide Composites

Insufficient interfacial interaction between nanoconductive materials and polymer matrices severely limits the mechanical, electrical, and pressure-sensing properties. Carbon nanotubes (CNTs), widely used as polymer reinforcements due to their excellent properties, can significantly enhance the mechanical performance of nanocomposites by improving the interfacial interactions with the matrix. Given the diversity of functionalized CNTs, a systematic study of their interfacial bonding mechanisms is of great importance for both scientific research and engineering applications. To this end, this study employs molecular dynamics simulations to investigate the interfacial characteristics and mechanical responses of functionalized CNT/polyimide (PI) systems. The results demonstrate that functionalization treatments significantly enhance both the interfacial interaction and the shear performance of CNT/PI nanocomposites. Specifically, the interfacial shear strength of the carboxylated CNT/PI composite reaches 269.83 MPa, representing a 20% improvement; furthermore, this property further increases with higher functional group content. This work elucidates the influence of functional group type and content on the interfacial shear performance of CNT/PI composites at the atomic scale, providing new physical insights.