Embrittlement Mechanisms of Nylon 66/Organoclay Nanocomposites Prepared by Melt-Compounding Process

Nylon 66 nanocomposites with different smectite clay loadings were prepared by conventional melt compounding process. The fracture toughness decreases with increasing clay content, which is a direct result of reduced plastic zone size at the crack tip region. The fracture mechanisms were studied using double-notched four-point-bending (DN-4PB) technique. A constraining effect from nanoclay fillers on plastic deformation of matrix is revealed by transmission electron microscopy (TEM). Micron-sized and submicron voids could be observed around the clay platelets. The voids coalesce and form premature cracks that promote crack propagation, thus reducing toughness.