Investigations on the influence of multiple extrusion on the degradation of polyolefins

• Investigations of polyolefin degradation induced by thermo-mechanical stress. Analysis changes in molecular weights and stabilizer concentrations via HT-GPC-IR HPLC-QTOF-MS. Determination molecules with odd-numbered alkane species related to HDPE TD-GC-MS. oxidized branched The importance mechanical recycling polymers has increased within the last decades, especially due numerous regulations governments all over world. Hereby quotas are enforced pave way towards a closed loop recycling. During its lifetime, exposed multiple environmental factors, which can already induce degradation. However, major factor that needs be taken into account is stress during process, may have significant impact on quality recyclates as well. In present work, polyolefins (high-density polyethylene polypropylene) were artificially continuous extrusion at varying speeds absence or presence stabilizers analyze extent contributes processes. These samples analyzed for low-molecular-weight markers thermodesorption gas chromatography high-performance liquid (both coupled mass spectrometric detection). Depending stress, occurrence linear chains was revealed samples, alkanes polypropylene samples. Correlations weight (determined high temperature gel permeation chromatography) decreasing could demonstrated.