PLASTIC-VISCOELASTIC CONSTITUTIVE EQUATION TO REPRESENT THE RHEOLOGICAL BEHAVIOR OF CONCENTRATED SUSPENSIONS OF SMALL PARTICLES IN POLYMER MELTS

The rheological properties of concentrated suspensions of small particulates in polymer melts are critically discussed. These systems give the appearance of a yield value in steady shear flow but also show many typical responses of a viscoelastic fluid. A tensor constitutive equation is developed to represent the behavior of such systems which combines a tensor yield criterion with a non-linear viscoelastic model. The response of this model is considered in both simple shear flow and uniaxial elongational flow. © 1979.