By Associated Polymer Labs, Inc.
A great test package, for incoming raw material resins, and to determine the viscosity as a function of temperature. In order to successfully predict the processibility of polymer melts, it is important to characterize the viscoelastic properties and the temperature dependency.
The frequency sweep provides information about the molecular weight distribution (MWD) and the weight average molecular weight (Mw). As the crossover frequency decreases the MWD is increasing. The viscosity at lower frequencies, 0.1 rads/sec, is related to the Mw of the polymer.
The temperature ramp provides the dependency of viscosity and insight of the materials melt strength. Also, when a low frequency is used, 1 rad/sec) the test is very sensitive to branching, both long and short, and the materials structure.
This package is available in both cgs and SI units.
Example file: also available in Excel and Quattro.
RE: Polyethylene Melt Rheology
Rheological properties were measured as a sequence test method in accordance with ASTM D 4440-95a Standard Practice for Rheological Measurement of Polymer Melts Using Dynamic Procedures, and International Standard ISO 6721-10 Determination of dynamic mechanical properties- Part 10- Complex shear viscosity using a parallel plate oscillatory rheometer.
Typical report has a summary of testing and instrument conditions:
Low density Polyethylene, FS @ 190C
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