Interfacial delamination between semicrystalline polymers and filler materials by coarse-grained molecular dynamics simulations

Understanding the interfacial delamination between semicrystalline polymers and filler materials is essential for improving the mechanical properties of polymer composites. While interfacial delamination is affected by interfacial interactions and polymer crystallinity at the interface, experimental observations of polymer orientation and its evolution during deformation remain challenging. In this study, coarse-grained molecular dynamics simulations are conducted to model the stretching of lamellar-structured semicrystalline polyethylene on a filler surface to elucidate the effects of different orientation relationships and interfacial adsorption strengths on the delamination behavior. In the edge-on model, in which the polymer lamellae are oriented perpendicular to the filler surface, the polymer detaches readily under strain and voids grow perpendicular to the stretching direction. In the flat-on model, in which the polymer lamellae are oriented parallel to the filler surface, with an amorphous layer adjoining the surface, the polymer does not detach easily during stretching and voids grow parallel to the stretching direction. The stress in the edge-on model increases rapidly and peaks at a higher value than that in the flat-on model. These simulation results advance our understanding of molecular-scale deformation and fracture processes in semicrystalline polymer–filler composites. • The interfacial delamination process between a crystalline polymer and a filler is investigated using coarse-grained molecular dynamics simulations. • In the delamination process of the edge-on model, where the polymer chains are oriented parallel to the interface, void growth parallel to the interface (perpendicular to the stretching direction) with little deformation of the polymer is observed. • In the delamination process of the flat-on model, where amorphous layers face the interface, void growth perpendicular to the interface (parallel to the stretching direction), accompanied by polymer deformation, is observed.