Berlin 2012 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 38: Focus: Rheology II (joint focus with DRG)
CPP 38.4: Vortrag
Freitag, 30. März 2012, 10:30–10:45, C 130
Chromatographic, spectroscopic and rheological characterization of long chain branching induced by thermo-oxidative degradation of low-density polyethylene — •Victor Hugo Rolon-Garrido1, Martin Zatloukal2,3, and Manfred H Wagner1 — 1Chair of Polymer Engineering/Polymer Physics, TU Berlin, Fasanenstrasse 90, D-10623 Berlin, Germany — 2Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, TGM 275, Zlin 76272, Czech Republic — 3Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcirnou 3685, 760 01 Zlin, Czech Republic
Low-density polyethylene was thermo-oxidatively degraded, i.e. degraded in the presence of air, by a one thermal cycle (1C) treatment during times between 30 and 90 minutes, and by a two thermal cycles (2C) treatment, i.e. after storage at room temperature an already previously degraded sample was further degraded during times between 15 and 45 minutes. Changes in the molecular weight distribution were detected by GPC and the intrinsic viscosity. Branching was confirmed by FTIR measurements. The enhanced strain hardening effect observed in uniaxial extension experiments presents a decisive evidence for an increased long-chain branching (LCB) content in both 1C and 2C samples. Elongational viscosity data were analyzed by the MSF and the Wagner-I model. It can be stated that elongational rheology is a powerful method to detect structural changes due to thermo-oxidative degradation.