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Molecular and morphological parameters governing yield failure of PE pipe materials [PE]


Plastic Pipes Conference Association # 2012 Barcelona

Anna M. Hartl, A. Buryak and R.W. Lang

The ductile behaviour of PE in Region I of the pipe failure regime is mainly governed by the time/ and temperature-dependent yield stress of the polymer [1]. Two different deformation mechanisms are relevant in PE. One governing shorter times and/or lower temperatures and the other longer times and/or higher temperatures, the latter being relevant for the long-term ductile failure behaviour of PE pipes. For the former, clear structure-property relationships were elaborated in literature. However, for the latter hardly any studies are available. This paper presents an accelerated method to characterize the ductile failure of PE pipes and tries to identify its limits and applicability. Furthermore as a first attempt the structures of three model PE pipe grades are linked to their long-term ductile failure properties.

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