Isothermal Flow of Purely Viscous Non-Newtonian Fluids

ISOTHERMAL FLOW OF PURELY VISCOUS NON-NEWTONIAN FLUIDS [Pg.9]

The transport properties of polymeric materials which distinguish them most from other materials are their flow properties or rheological behavior. There are many differences between the flow properties of a polymeric fluid and typical low molecular weight fluids such as water, benzene, sulfuric acid, and other fluids, which we classify as Newtonian. Newtonian fluids can be characterized by a single flow property called viscosity (/r) and their density (p). Polymeric fluids, on the other hand, exhibit a viscosity function that depends on shear rate or shear stress, time-dependent rheological properties, viscoelastic behavior such as elastic recoil (memory), additional normal stresses in shear flow, and an extensional viscosity that is not simply related to the shear viscosity, to name a few differences. [Pg.9]

The emphasis in this chapter is on the viscous behavior of polymeric fluids and in particular their pseudoplastic behavior. The chapter is arranged in the following manner. First, in Section 2.1 we review the definition of a Newtonian fluid, and then we present empiricisms for describing the viscosity of polymeric fluids. In Section 2.2 [Pg.9]

Polymer Processing Principles and Design, Second Edition. Donald G. Baird and Dimitris I. ColUas. 2014 John Wiley Sons, Inc. Published 2014 by John Wiley Sons, Inc. [Pg.9]

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