Reinhold W. Lang, Patrick R. Bradler, Joerg Fischer, Dominik Poehlmann, Steven Schmidt, Ansgar Niehoff
Papers # 2016 Berlin
In the present paper, a highly effective test and characterization concept for polymer recyclate materials is proposed and validated. Based on the proposed methods, a study was carried out to investigate the potential of in-plant and post-use PE recyclates from various applications to be utilized in PE recyclate containing pipes. The recyclate contents ranged from about 50 to essentially 100 m%, the remaining portion being a PE 100 virgin resin. As benchmark and reference also included in the study was the neat PE 100 virgin material.
In total, 15 post-use PE recyclate compounds, 1 in-plant PE recyclate compound plus a neat PE 100 virgin material were systematically investigated and characterized in terms of key molecular and morphological characteristics (relative changes in mean molecular mass and in molecular mass distribution, degree of crystallinity and melting temperature, oxidation onset temperature) as well as their slow crack growth behavior under cyclic loading conditions. Excellent material structure-property correlations could be established that allow for a quick ranking of PE recyclate compound grades. The methodology and the results may also be used in terms of a first quantitative service-life assessment regarding the utilization of such materials for non-pressure and pressure pipes.