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A new rheometer measuring infrared dichroism in molten polymers subjected to transient and steady shear flow
Author(s) -
Skytt M.L.,
Färnert G.,
Jansson J.F.,
Gedde U. W.
Publication year - 1996
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10569
Subject(s) - rheometer , materials science , rheology , shear rate , dichroism , shear (geology) , shear flow , composite material , rheometry , fourier transform infrared spectroscopy , polymer , siloxane , thermodynamics , chemical engineering , optics , physics , engineering
A rotational parallel plate rheometer that enables simultaneous measurement of the transient or steady‐state rheological properties and infrared dichroism was designed and constructed to study orientation in molten polymers. Measurements can be carried out at shear rates between 0.05 and 300 s −1 and at temperatures between 20 and 300°C. Both shear stress and axial normal force together with dichroism are continuously measured during shear flow. Infrared dichroism data for polypropylene showed excellent agreement with data obtained with a FTIR‐instrument. The Hermans orientation function for molten poly(dimethyl siloxane) at steady state showed a strong shear‐rate dependence in the region 0.1−20 s −1 . Rheological data for molten poly(dimethyl siloxane) agrees with data obtained from a conventional rheometer.