Study on the Viscoelastic Properties of Polymer Melts in Shear
碩士 === 國立臺灣科技大學 === 化學工程研究所 === 83 === The objective of this work is to study the viscoelastic properties of polymer melts, including PP, PS and LDPE under shear and elongational deformation. The shear viscosity of polymer melts were measured by a rheomet...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
1995
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| Online Access: | http://ndltd.ncl.edu.tw/handle/94099890965939772911 |
| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程研究所 === 83 === The objective of this work is to study the viscoelastic
properties of polymer melts, including PP, PS and LDPE under
shear and elongational deformation. The shear viscosity of
polymer melts were measured by a rheometrics dynamic analyzer
(RDA) and a capillary rheometer. The modified Cross model was
employed to correlate the shear viscosity data for the various
polymer melts. The elongational viscosity of polymer melts were
calculated from the shear viscosity data by both the Cogswell
model and the Binding model. Since the experimental data of
elongational viscosity at high deformation rates were not
available, the calculated elongational viscosities were
compared to those predicted by the Larson model. The
experimental data of elongational viscosity obtained by the
melt spinning method at moderate deformation rates were also
compared to those predicted by the Larson model. The results
were found to be satisfactory. The fact that the Trouton ratio
predicted by the Larson model is close to the theoretical value
of three assures that the Larson model is reliable. In the
calculation of elongational viscosity by the Cogswell model, it
was found that the true shear viscosity data were more relevant
than the apparent viscosity data.The elongational viscosities
calculated by the Binding model were found to be more closer to
those predicted by the Larson model than those calculated by
the Cogswell model.
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