In recent years, several developments have made it possible to predict the detailed molecular structure of a polymer based on polymerization conditions and to use this knowledge of the structure to predict rheological properties. In addition, new techniques for using rheological data to infer molecular structure have alsobeen developed. Soon, it will be possible to use this new knowledge to design a molecular structure having prescribed processability and end-product properties, to specify the catalyst and reaction conditions necessary to produce a polymer having this structure, and to use rheology to verify that the structure desired has, in fact, been produced. This book provides a detailed summary of state-of-art methods for measuring rheological properties and relating them to molecular structure. Contents: Structure of Polymers, Polymerization Reactions and Processes, Linear Viscoelasticity - Fundamentals, Linear Viscoelasticity - Behavior of Molten Polymers, Tube Models for Linear Polymers - Fundamentals, Tube Models for Linear Polymers - Advanced Topics, Determination of Molecular Weight Distribution Using Rheology, Tube Models for Branched Polymers, Nonlinear Viscoelasticity, Tube Models for Nonlinear Viscoelasticity of Linear and Branched Polymers