Rheological properties of molten poly(ethylene terephthalate)

✍ Scribed by D. R. Gregory

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 445 KB
• Volume: 16
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1972.070160616

✦ Synopsis

The complete steady-state flow properties of molten poly(ethy1ene terephthalate) for shear stresses 34.14 X 1CP dynes/cm* 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(ethy1ene terephthalate) a t shear stresses S4.14 X 1P dynes/cm'. 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(ethy1ene terephthalate) with a 0.6 I.V., a 0.0025 change in Z.V. accounts for about the same change in melt viscosity as a l 0 C change in temperature.