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.

Elongational Viscotiy of Polymer Composite Including Hydrophilic or Hydrophobic Silica Nano-Particles

“…Finally, the samples were broken after showing necking phenomenon. This decreasing behavior of viscosity agreed with the results reported in the previous paper [4][5][6][7][8][9] and the strain-softening origin seemed to be explained by the idea that undeformed particles generate complex flows around the particles.…”

“…Elongational flow behavior of ABS (AcrylonitrileButadiene-Styrene) resins was often reported. [1][2][3] In general, it is known that ABS exhibits a weaker strain-hardening in elongational flow which is similar to that of polymer composite systems [4][5][6][7][8][9] than matrix AS (Acrylonitrile-Styrene Copolymer).…”

“…8) Most ABSs and composite systems show weaker strain-hardening in elongational flow with decreasing strain rate. However, it has been reported in a few reports 1,2) that some ABS resins showed a stronger strain-hardening with decreasing strain rate, whose mechanism was not successfully interpreted due to some complex effects such as particle deformation and aggregation of butadiene particles in AS matrix.…”

“…[4][5][6][7][8][9] All of these showed a weaker strainhardening than the matrix polymer and the stronger strainhardening with increasing strain rate. One exception is a claydispersed MAPP (MA (maleic anhydride) modified PP (Polypropylene)) system, which showed a stronger strainhardening than general commercial PP, especially at low strain rates.…”

Rheological properties of poly(methyl methacrylate)/rigid ladderlike polyphenylsilsesquioxane blends

“…Takahashi et al found that glass-fiber-filled LDPE exhibited strainsoftening properties. 24 Takahashi et al also reported that the strain-softening was observed in ABS copolymers containing hard crosslinked butadiene particles. 25 The presence of hard particles seemed to be the key factor in both these cases, which was responsible for strain-softening properties.…”