Interfacial voids, separation interface

In the separation of an adhering system at or near an interface, in terms of a craze mechanism, there will be four differences from separation within a bulk polymer. One is, that interfacial voids (or proto-voids) may exist. These can act as cavitation nuclei and interfacial craze formation, starting from such nuclei, would be orders of magnitude more rapid than crazing by homogeneous nuclea-tion. Such cavitation could also be more rapid than the processes that occur in the Taylor instability mechanism, particularly if it should happen that the voids at the interface formed a two-dimensional continuum. Patches of low-energy matter in the solid surface can also be loci of void initiation, even if no voids are present before loading. 

A significant difference between the interfacial events occurring here and those in previous studies, is that the earlier work always involved macroscopic separation of surfaces. Here, the fiber and matrix remain in relatively intimate contact after debonding, which very likely influences the intensity and time dependence of the resulting emission. For example, we expect possible quenching mechanisms involving the nearby surfaces and gases in the narrow void created by the broken interface, which would tend to reduce the intensity and duration (decay) after a separation event. 

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