In situ small-angle X-ray and neutron scattering measurements on a blend of deuterated and hydrogenated polyethylenes during uniaxial drawing

Abstract

In situ small-angle X-ray and neutron scattering (SAXS and SANS) measurements were conducted on an isotropic blend of deuterated polyethylene and hydrogenated polyethylene (HPE; 3 wt%) during uniaxial drawing at 125 °C to clarify the formation mechanism of the shish-kebab from the isotropic film. In the early stage of drawing, two-spot scattering patterns were observed along the drawing direction in both the SAXS and SANS patterns, and the patterns gradually shifted to lower angles, which indicated that the isotropic lamellar crystals rotate and orient to align and that the long period increases because of the elongation of the amorphous region. In the late stage of drawing, the long-period peak gradually shifted to higher angles and the peak width broadened and finally disappeared at the local drawing ratio R D ∼6.0, suggesting fragmentation of lamellar crystals (kebabs) and pulling of the polymer chains out of the kebab. However, only the 2D SANS patterns exhibited streak-like scattering in the direction normal to drawing above R D ∼2.4, suggesting the preferential orientation and stretching of the HPE chains to form the extended chain crystal (shish). By analyzing the SANS data using the multicore-shell cylinder model, the diameter of the shish that consisted of HPE decreased from 9.0 to 4.5 nm when the drawing was increased from R D =3.8 to 8.0. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.