Relaxation in Physical and Mechanical Behavior of Polymers

Explores the nature of relaxation phenomena in polymers on the basis of time-temperature equivalence. Its role in the physical and mechanical behavior of polymers materials and fundamentals of thermoplastics processing are discussed. Four appendixes detail thermo-mechanical methods to study relaxation in polymers, structure of both amorphous and semi-crystalline polymers, and unified approach to describe deformation of polymeric materials.

Introduction 1. Viscoelasticity and relaxationMechanical models of a viscoelastic body Molecular–kinetic foundations of physico-mechanical behaviour of amorphous solids Viscoelasticity and relaxation properties of amorphous polymers The principle of temperature–time superposition 2. Relaxation transitions in some polymers Amorphous polymers Relaxation ß-transition Relaxation a-transition and vitrification 'Liquid–liquid' relaxation transition (ll-transition) On the relationship of ß-, a-, and ll-transitions Plasticized polymers Intrastructural (molecular) plastification Interstructural plasticization Semi-crystalline polymers 3. The role of relaxation processes in phase transformations of polymers 4. Relaxation aspects of plastic deformation of polymers Polymeric glass Semi-crystalline polymers 5. Relaxation of deformed polymersRelaxation of the latent energy of deformed polymer glasses Relaxation of the dimensions of deformed polymer glasses Physical ageing of deformed polymeric glasses 6. The ‘brittleness–plasticity’ transition and the low-temperature boundary of plasticity of polymers 7. Relaxation processes during processing of thermoplastic polymers Monolithization of powders in the P–T mode Monolithization of powders in the ¿–¿ mode

Maxim Arzhakov, Moscow State University, Moscow, Russia