The deformation mechanism of polyphenylquinoxaline films

The deformation mechanism of polyphenylquinoxaline (PPQ-E) film has been st udied by theoretical prediction and microscopic observation. The entangleme nt density, estimated from the plateau modulus on the dynamic mechanical pr operty curves, was used to predict the deformation mechanism of PPQ-E. Pola rized light microscope (PLM) was used to observe the morphology of the PPQ- E film during tensile deformation, it is found that the deformation mechani sm of PPQ-E is both crazing and sheer yielding, which is in agreement with the prediction by entanglement density. The craze morphology of PPQ-E is ma inly of fibril craze consisting of micro-fibrils and micro-voids as observe d by transmission electron microscope (TEM). The interface between the bulk and craze is distinct. Multiple crazes, blunting of craze tips and homogen eous deformation zones have also been observed. (C) 2001 Elsevier Science L td. All rights reserved.