Rheological Properties of Some Thermoplastic Elastomers

Abstract

We studied the characteristics of some thermoplastic elastomers (TPEs) using measurements of the temperature dispersion of the complex tensile modulus in the solid state, and the dynamic viscoelasticity and elongational viscosity in the molten state. The TPE samples included PVC/plasticizer-type TPEs and polymer alloy-type TPEs. The storage and loss shear moduli, G′ and G″, exhibited a power-law dependence on the angular frequency ω for most of the TPE samples measured. These findings indicate that these TPEs have long time relaxation mechanisms due to a self-similar fractal-like structure. The elongational viscosity behavior was different between the PVC/plasticizer-type TPEs and polymer alloy-type TPEs. The PVC/plasticizer-type TPEs exhibited strong strain hardening, while the other TPEs did not show any strain hardening. This difference is attributed to the morphology in these TPEs.