Structure Change of Oriented Polyethylene by Redrawing

Abstract

This work was made in order to examine the propriety of the structure model of oriented polyethylene proposed by the authors. Drawn and annealed plates of polyethylene showing four point patterns in small angle x-ray diffraction were redrawn along the fiber axis and studied by x-rays. By redrawing the c-axis was made parallel to the redrawing axis, while inclination of lamellae was not changed markedly. The long spacing calculated from the height of the four spots according to the Bragg equation was increased with draw ratio which exceeded slightly the macroscopic draw ratio of the specimen. At high redrawing horizontal streaks appeared in small angle patterns below the spots corresponding to the interlamellar distance. These results are interpreted by the structure model by considering that macroscopic elongation is produced by glide on grain boundaries and inhomogeneous elongation of amorphous layers accompanied with generation of microcracks.