A COMPARISON BETWEEN RHEOLOGICAL DATA FOR POLYMER MELTS AND SPRIGGS 4-CONSTANT VISCOELASTIC MODEL

An experimental and analytical study was made to determine how well the material functions, derived from the Spriggs four‐constant viscoelastic model, could describe the rheological properties of polymer melts. Viscosity and elasticity of selected polymer melts were experimentally determined in the rotational and oscillatory modes using a Weissenberg Rheogoniometer. The Spriggs model was chosen for study because of its success in describing experimental data for polymer solutions and because of its uniqueness in combining results from molecular theory with results from the theories associated with continuum mechanics. It was found that the model provides a good description of the rheological data for polymer melts and that some of the model parameters depend upon the molecular characteristics of the polymer. Since this model contains a small number of well defined constants, it should be useful in developing dimensionless engineering correlations for the complex flows encountered in processes of industrial importance. Deviations between the theoretical and experimental results are discussed and deficiencies of the model noted. Copyright © 1969 American Institute of Chemical Engineers