Unexpected shish-kebab structure in a sheared polyethylene melt

Phys Rev Lett. 2005 Mar 25;94(11):117802. doi: 10.1103/PhysRevLett.94.117802. Epub 2005 Mar 22.

Abstract

Scanning electron micrographs of a solvent-extracted sheared polyethylene (PE) blend revealed, for the first time, an unexpected shish-kebab structure with multiple shish. The blend contained 2 wt % of crystallizing ultrahigh molecular weight polyethylene (UHMWPE) and 98 wt % of noncrystallizing PE matrix. The formation of multiple shish was attributed to the coil-stretch transition occurring in sections of UHMWPE chains. Synchrotron x-ray data provided clear evidence of the hypothesis that multiple shish originate from stretched chain sections and kebabs originate from coiled chain sections, following a diffusion-controlled crystallization process.