Rheotens-mastercurves and elongational viscosity of polymer melts

✍ Scribed by Manfred H. Wagner; Bertrand Collignon; Jérôme Verbeke

• Publisher: Springer-Verlag
• Year: 1996
• Tongue: English
• Weight: 725 KB
• Volume: 35
• Category: Article
• ISSN: 0035-4511
• DOI: 10.1007/bf00396038

✦ Synopsis

In a Rheotens experiment, the tensile force needed for elongation of an extruded filament is measured as a function of the draw ratio. For thermo-rheologically simple polymer melts, the existence of Rheotens-mastercurves was proved by Wagner, Schulze, and G(Sttfert (1995). Rheotens-mastercurves are invariant with respect to changes in melt temperature and changes in the average molar mass. By use of purely viscous models, we convert Rheotens-mastercurves of a branched and a linear polyethylene melt to elongational viscosity as a function of strain rate. The resulting elongational viscosity from constant force extension experiments is found to be in general agreement with what is expected as steady-state viscosity of polyethylene melts measured in either constant strain-rate or constant stress mode.