Strain-hardening property and internal deformation of polymer composite melts under uniaxial elongation

Abstract

Uniaxial elongational viscosity of low density polyethylene (LDPE) gave the strain-hardening property. However, talc-filled LDPE showed almost no strain-hardening property and glass-fiber-filled LDPE exhibited the strain-softening property. The cause of almost no strain-hardening property or strain-softening property was discussed from flow observation of internal deformation using visual model experiments. Silicone gums including a glass bead or a glass fiber with a black silicone gum marker were elongated. The internal strain in a glass-bead-filled system was larger than the external strain along the elongational axis, and the received internal strain was larger around a particle than far way from a particle. The internal strain in a glass-fiber-filled system did not depend on the location when the initial orientation of the fiber was perpendicular to the elongational direction. While, the received internal strain next to the fiber without the both edges was almost none when the initial fiber was parallel to the elongational direction. Nonuniformities of internal flow by the addition of fillers seem to be associated with no strain-hardening property or strain-softening property.