Treatment of Rheological Data Using Models

Prior to using a model for description of rheological data, it would be desirable to 

How reliable are the data Are the data reproducible Are the measurement techniques reliable Are the test samples reproducible, reliable, and suitable for rheological measurements  

Plot the data (ct — y)-look for trends in data and artifacts of rheometer. Sometimes, most, but not all, of the data can be used for subsequent analysis. If the data are not reliable, why fit models  

Rheological model (a) Is it appropriate for the experimental data (b) How reliable is the model parameter estimation software Has the reliability of the software been checked (c) What are you looking for in the data (e.g., effect of temp.) (d) Compare experimental data with a model s predictions because values often do not indicate the appropriateness of the model for the selected data  

Abdel-Khalik, S. 1., Hassager, O., and Bird, R. B. 1974. Prediction of melt elasticity from viscosity data. Polymer Eng. and Sci. 14 859-867. 

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