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Elongational Viscosity and Foaming Behavior of PP Modified by Electron Irradiation or Nanotube Addition
Author(s) -
Pötschke Petra,
Krause Beate,
Stange Jens,
Munstedt Helmut
Publication year - 2007
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200750858
Subject(s) - materials science , irradiation , polypropylene , viscosity , composite material , branching (polymer chemistry) , nanotube , mixing (physics) , carbon nanotube , shear viscosity , polymer chemistry , chemical engineering , physics , quantum mechanics , nuclear physics , engineering
Summary : In this study, two different routes were chosen which are expected to influence the elongational viscosity and, thus, the foaming behavior of polypropylene (PP). Electron irradiation of a linear PP was performed at room temperature using different doses. Enhanced long‐chain branching was observed with increased irradiation dose. In addition, a linear PP was filled with 5 wt% multiwalled carbon nanotubes (MWNT) by melt mixing at 200 °C. These modified PP materials were investigated with respect to their shear and elongational behavior. After foaming, irradiated PP led to an expansion factor which is about 60% higher than that of the non‐irradiated product. In case of PP filled with 5 wt% MWNT the value of the expansion factor is about 70% higher than that of pure PP expanded under the same conditions. The cell structure is much finer in both cases as compared to unmodified PP.