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Rheological properties of molten poly(ethylene terephthalate)
Author(s) -
Gregory D. R.
Publication year - 1972
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.1972.070160616
Subject(s) - materials science , rheology , viscosity , poly ethylene , superposition principle , thermodynamics , shear rate , time–temperature superposition , ethylene , temperature dependence of liquid viscosity , composite material , polymer chemistry , shear (geology) , intrinsic viscosity , relative viscosity , chemistry , organic chemistry , polymer , catalysis , physics , quantum mechanics
The complete steady‐state flow properties of molten poly(ethylene terephthalate) for shear stresses ≦4.14 × 10 6 dynes/cm 2 were determined. A single, complete master curve had been constructed in earlier work by Gregory and Watson; the curve interrelates the shear stress, shear rate, temperature, and molecular weight (inherent viscosity) by using a temperature superposition scheme from the literature and a similar molecular weight superposition scheme. Equations in agreement with theory and with other published experimental data were derived from the master curve. Results presented here make possible the direct calculation of the melt viscosity of poly(ethylene terephthalate) at shear stresses ≦4.14 × 10 6 dynes/cm 2 . The effects of a unit temperature change and/or a unit change in inherent viscosity ( I. V. ) on the melt viscosity were determined. For poly(ethylene terephthalate) with a 0.6 I . V ., a 0.0025 change in I . V . accounts for about the same change in melt viscosity as a 1°C change in temperature.