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Melt flow indexer evidence of high‐temperature transitions in molten high‐density polyethylenes
Author(s) -
Hussein Ibnelwaleed A.,
Williams Michael C.
Publication year - 2003
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.13278
Subject(s) - high density polyethylene , materials science , polystyrene , extrusion , polyethylene , atmospheric temperature range , amorphous solid , composite material , melt flow index , glass transition , melting temperature , range (aeronautics) , polymer , thermodynamics , chemistry , copolymer , crystallography , physics
A melt flow indexer (MFI) was used to investigate high‐temperature transitions in melts of high‐density polyethylene (HDPE). The MFI data were obtained in the range 190–230°C. These transitions were found in the MFI at about 210 and 225°C and reproduced in a Haake melt blender. Polystyrene was used in the blender experiment to demonstrate typical amorphous behavior. For HDPE melts, the MFI–temperature behavior and the torque–temperature data of the blender were found to be alternative images of the same anomalous temperature dependency in the range 210–225°C. Also, the Haake melt blender was able to reproduce the 150°C transition observed by Kolnaar and Keller in the extrusion of HDPE. Regardless of the simplicity of the MFI device, results are in agreement with our previous DSC findings. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1309–1313, 2004