Study on the crystallization behaviour of polyethylene grafted onto carbon nanotubes using molecular dynamics simulation

Abstract

ABSTRACT The mechanical property of polymer can be effectively changed by grafting polymer onto the surface of nano-fillers. In this paper, the crystallization behaviour of polyethylene grafted on carbon nanotubes with different grafting densities have been explored in detail by using molecular dynamics simulation. During the crystallization process, the crystallinity, the site order parameter, the mean square displacement, the radius of gyration and the bond-orientational order parameter were recorded. The results show that higher grafting density results in stronger crowding effect and weaker mobility of molecular chain. The ultimate crystallinity of the polymer increases with the increase of grafting density. The orientation of crystal bond indicates that the polymer with higher grafting density tends to be perpendicular to the surface of nano-fillers. Those findings in this work are of great values for further exploring reinforcement mechanism and also the microscopic mechanism of crystallization behaviours of polymer nanocomposites.