Extrapolating deformation behaviour of rubber to high rates and high pressures

Abstract

An important and oft-utilised viscoelastic property of polymers is their conformance to the time–temperature superposition principle. However, it is well established that in the glass transition zone, where both the local segmental and global chain modes contribute to the response, polymers are thermorheologically complex. Extrapolations of mechanical and other properties through the glass transition zone thus entail large errors. An alternative procedure that accounts for the pressure and volume dependences is based on the empirical fact that both local segmental and global relaxation times of polymers are a function of the product variable, TV ^γ , where T is temperature, V is specific volume, and γ is a material constant. The utility of this scaling property is described.