Polymer Crystallization during shear flow

We evaluated the effect of molecular weight on the formation of a shish–kebab morphology on a wide spatial scale. Here we examined blended polyethylene with 97 wt% deuterated polyethylene and 3 wt% protonated polyethylene comprising molecules with a range of molecular weights. Measurements were conducted with various X-ray and neutron scattering techniques. The nanometer-scale analysis revealed that the crystal lattice is also independent of the molecular weight. Moreover, small-angle X-ray and neutron scattering measurements did not reveal any influence of molecular weight. On the other hands, strong streak-like neutron scattering was observed perpendicular to the drawing direction. The multicore-shell cylinder model was used to evaluate the parameters of the shish structure: the radius of the core cylinders increased with the molecular weight while the number of core cylinders decreased with the molecular weight. On the other hand, the micron-scale analysis using ultra-small-angle X-ray and neutron scattering measurements revealed that the micrometer-scale fibril structure is independent of the molecular weight.