Time–temperature superposition

Abstract: The Nature of Viscoelastic Behavior. Illustrations of Viscoelastic Behavior of Polymeric Systems. Exact Interrelations among the Viscoelastic Functions. Approximate Interrelations among the Linear Viscoelastic Functions. Experimental Methods for Viscoelastic Liquids. Experimental Methods for Soft Viscoelastic Solids and Liquids of High Viscosity. Experimental Methods for Hard Viscoelastic Solids. Experimental Methods for Bulk Measurements. Dilute Solutions: Molecular Theory and Comparisons with Experiments. Molecular Theory for Undiluted Amorphous Polymers and Concentrated Solutions Networks and Entanglements. Dependence of Viscoelastic Behavior on Temperature and Pressure. The Transition Zone from Rubberlike to Glasslike Behavior. The Plateau and Terminal Zones in Uncross-Linked Polymers. Cross-Linked Polymers and Composite Systems. The Glassy State. Crystalline Polymers. Concentrated Solutions, Plasticized Polymers, and Gels. Viscoelastic Behavior in Bulk (Volume) Deformation. Applications to Practical Problems. Appendices. Author & Subject Indexes.

Abstract: Preface. Introduction to Damping. Modeling the Dynamic Mechanical Behaviour of Viscoelastic Materials. The Effects of Temperature and Frequency on Complex Modulus Properties. Measurement of Complex Modulus Properties. Numerical Analysis of Measured Complex Modulus Data. The Complex Modulus Behaviour of Typical Polymeric Materials. Harmonic and Non-harmonic Response of Simple Viscoelastic Systems. Controlling Vibration using Viscoelastic Materials. References. Symbols for Chapter 8. Selected Computer Programmes. Units and Dimensions. Author Index. Subject Index.

Abstract: A number of commercial semicrystalline polymers have been investigated for ageing effects occurring after quenching from a high temperature T0 to various temperatures between −170°C and T0; generally T0 was kept above 100°C. Before testing the samples were annealed overnight at a temperature Ta higher than T0 in order to stabilize the crystallinity. After quenching the mechanical creep properties (torsion) as well as the volume relaxation were measured as functions of the time te elapsed after quenching. The semicrystalline polymers showed strong ageing effects at temperatures below as well as above the conventional glass transition temperature Tg of the material. These effects could be described in detail using the model of an extended glass transition, introduced several years ago1. It is assumed that the crystalline phase reduces the segmental mobility in the amorphous phase, the more so the closer to the crystal surface. Therefore, the amorphous phase no longer has a single Tg but a Tg-distribution. The experiments suggest that the upper Tg, TUg, may be much higher (>100°C) than the lowest, TLg. Furthermore, the temperature range should be divided in four characteristic regions: Region 1 (T

Abstract: Structure of polymers crystalline and amorphous states in polymers rubber elasticity stress-strain relations for ideal solids and ideal liquids linear viscoelasticity - viscoelastic functions dynamic viscoelastic functions experimental determination of viscoelastic properties viscoelastic behaviour of polymers above the glass-transition retardation and relaxation spectra viscoelastic models molecular models of the viscoelastic polymers viscoelasticity of glassy and semicrystalline polymers flow behaviour of polymer melts and solutions yield crazing and fracture reinforced polymers multiaxial analysis of linear viscoelastic stress flexion and torsion of viscoelastic rods.