Damping Behavior of Highly Entangled High Density Polyethylene after Uniaxial Step Strains

Abstract

Stress relaxation after a large step strain is conducted for melts of highly entangled high density polyethylene in the uniaxial deformation by a conventional tensile tester. Prior to the stress relaxation tensile tests are made to confirm the uniformity of the elongation. The damping function for the melts in uniaxial deformation is almost identical or close to the prediction by the Doi-Edwards (DE) theory: Stronger damping than the DE prediction, which is often observed for highly entangled polymer melts in shear, is not observed in the uniaxial deformation.