The present monograph is intended as an introduction into a field which certainly did not receive proper attention in the past. It is one of the aims of this book to verify this suppo sition. The author hopes to show that the technique of the measurement of flow birefringence can fulfil an important com plementary task in polymer melt rheology. From this point it is expected that the present monograph will attract the atten tion of polymer scientists in general, and of rheologists and process engineers in particular. Certainly, the fourth chapter will appeal to the latter group. As a teacher in polymer science and technology the author wants to address also the group of the graduate students. In fact, the standard knowledge acquired during usual university studies in chemistry, physics or engineering does not enable a quick start of research activities in the field of polymer melt rheology. Certainly, in this typically interdisciplinary field everyone can lay emphasis on matters which are familar to hirn because of his preceding education. Significant research activities, however, can only be generated on the basis of a more universal knowledge. In the absence of this knowledge beginners have to rely upon the guidance of their supervisors for an unduly long period. Otherwise they take the risk of losing too much of their costly time. This holds in particular for the experimentalists who cannot be dispensed from being familiar with the necessary theoretical background.

Inhalt
1 Survey of Experimental Results.- 1.1 Preparatory Considerations.- 1.2 Flow Birefringence Measurements.- References of Chapter 1.- 2 Quasi-Molecular Phenomenological Theories.- 2.1 Rubber Elasticity.- 2.2 The Linear Stress-Optical Relation.- 2.3 The Most Simple Rubberlike Liquid Model.- 2.4 More General Discussion of Quasi-Linear Models.- 2.5 Quasi-Linear Models Containing Adjustable Elements.- 2.6 A Theory Derived from a Different Basic Principle.- References of Chapter 2.- 3 Prospects for Predictions on a Moleculat Basis.- 3.1 General Introduction.- 3.2 Relaxion Processes in a Polmer Melt.- 3.3 General Flow Behavior of Polymer Melts.- References of Chapter 3.- 4 Industrial Applications.- 4.1 Molecular Orientation.- 4.2 Injection Moulding.- References of Chapter 4.- Appendix A: Linear Visco-Elasticity.- A.1 Hooke's Law in Complex Notation.- A.2 Stress Relaxation and Creep.- A.3 Elastico-Viscous Flow and Recovery.- A.4 Some Comments with Respect to the Interconversion of Material Functions.- A.5 Mechanical Spectra.- A.6 Interconversion Formulae Based on the Relaxation Time Spectrum.- A.7 Calculation of the Relaxation Time Spectrum from Experimental Material Functions.- References of Appendix A.- Appendix B: The Time-Temperature Superposition Principle.- B.1 Introduction.- B.2 The WLF-Equation.- B.3 The Free Volume Concept.- B.4 Unified Description of the Temperature Denpendence of the Zero-Shear Viscosity.- References of Appendix B.- Appendix C: The Measurement of Birefringence Effects.- C.1 Matrix Representation of Optical Components.- C.2 Calculations of Intensities of Beams Emerging from the Analyser.- C.3 How to Cope with Imperfections of Windows and Polarizing Prisms.- C.4 Description of the Modulator.- C.5 Problems with Quickly Changing Birefringence Effects.-References of Appendix C.