Viscoelasticity and microscopic motion in dense polymer systems

Abstract

The mechanical properties of condensed matter are generally divided into two classes: solids, such as metals or glasses, behave elastically; for small deformations the stress is proportional to the strain - Hooke's law is valid. Liquids display viscous behavior; in this case the stress is proportional to the change in strain, Newton's law persists. In contrast, the mechanical dynamical properties of polymers are extraordinarily versatile. Depending on the temperature or load time, the same polymer may display vitreous, rubberlike or fluid behaviour. This wide range of behaviour is known as viscoelastic.