Molecular weight component dependence of shish-kebab structure of polyethylene blends with X-ray and neutron scattering measurements covering a wide spatial scale

In this study, the authors evaluated the effect of molecular weight on the formation of a shish-kebab morphology on a wide spatial scale. Here the authors 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. The long spacing period of the correlation between lamellar crystals and amorphous phases is almost constant due to strong dependence of 97 wt% d-PE components, but increases with the molecular weight from neutron ones. Furthermore, 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.