ABSTRACT
Rheology is the study of flow by definition, and polymer melt rheology is basically concerned with the description of the deformation of polymer melts under the influence of applied stresses. Molten thermoplastics are viscoelastic materials in the sense that their response to deformation lies in varying extent between that of viscous liquids and elastic solids. In purely viscous liquids, the mechanical energy is dissipated into the systems in the form of heat and cannot be recovered by releasing the stresses. Ideal solids, on the other hand, deform elastically such that the deformation is reversible and the energy of deformation is fully recoverable when the stresses are released.
