Molecular dynamics simulation on the crystallization behavior of cyclic polyethylene affected by functionalized carbon nanotubes

In this work, the effects of functionalized carbon nanofillers (i.e., CNT-g-PE prepared by carbon nanotubes grafted with linear polyethylene) on the crystallization of cyclic polyethylene were revealed by molecular dynamics simulation, and compared with that of pure cyclic polyethylene(C-PE) and carbon nanotube / cyclic polyethylene blends(C-PE/CNT). The simulation results show that the CNT-g-PE has an anti-nucleation effect on the cyclic polyethylene, the crystallinity and crystallization rate of the C-PE/CNT-g-PE system are significantly lower than those of the other systems. This phenomenon can be explained by the topological effect when linear polyethylene chains grafted on carbon nanotubes are mixed with cyclic polyethylene. It is observed from the micro-scale that when the linear polyethylene chains are in contact with cyclic polyethylene, the cyclic chains are passed through by the linear chains to form a transient entanglement network, further affecting the dynamic process of the molecular chains. The diffusion and orientation of the cyclic polyethylene molecular chain are inhibited. This limits the crystal nucleation efficiency and growth kinetics. These simulation results not only support some experimental findings, but also confirm some microscopic phenomena that are difficult to observe in the experiment, which provides some inspirations for the experimental design of high-performance nanocomposite materials.