Polymer morphology and mechanism of macrocrack propagation on fracture surfaces

Abstract

Th0e relief of fracture surfaces of oriented monofilaments of nylon 66 has been studied with the help of both transmission and scanning electron microscopy. It has been shown that at different speeds of macrocrack propagation the relief of the so‐called mirror zone can show the original structural features of the material (e.g., the existence of supermolecular structures of the order of a micron, the influence of annealing, the distribution of micropores in the fibrillar amorphous regions) as well as effects connected with deformation processes at the tip of the crack, with discrete and auto‐oscillatory mechanisms of crack growth, the interaction of the macrocrack with the secondary fracture processes, etc.