Nanoscale elastic–plastic deformation in clay-reinforced nanostructured materials: The response of phase and structural morphology

The study described here combines materials science and engineering and mathematical analysis to fundamentally obtain insights underlying nanoscale deformation in polymer nanocomposites. The objective was achieved by examining the surface deformation response of two polymer nanocomposite systems with significant differences in ductility during scratching with a nanoindenter. The model host systems are a ductile polyethylene and a less ductile polypropylene. The model reinforcement material is nanoclay. The two systems are unique nanostructured materials because the distance between the individual clay layers is comparable to their thickness and also to the polymer segments. Thus, it is a morphology that is truly dominated by nanoscale features. Furthermore, we have used pressure-induced crystallization approach to alter the structure of the investigated two systems and study nanoscale surface deformation response. Our hypothesis is that the susceptibility to scratch deformation of nanostructured materials...