Nanoindentation and morphological studies on injection-molded nylon-6 nanocomposites

The nanoindentation behavior and morphology of the injection-molded specimens of nylon-6 (PA6)/clay nanocomposites prepared by melt-compounding have been studied in present study. The elastic and plastic properties as well as creep behavior of PA6 and its nanocomposites are comparatively evaluated as the function of clay loading by using nanoindentation technique. The anisotropic characteristics in mechanical properties are studied by indenting the injection-molded specimens in two different directions (i.e. parallel and perpendicular to the injection direction). The uneven distribution of both the clay nanofiller and the crystallinity of the polymeric matrix induced by melt-processing leads to the variation of the mechanical property of the nanocomposites in certain directions and locations within the molded specimens. The microstructural and morphological changes of PA6 upon incorporating with clay nanofiller are evidenced by transmission electron microscopy and small-angle X-ray scattering, which are closely correlated with the anisotropy of the mechanical properties observed by nanoindentation.