Analysis of the asymmetric 002 x-ray line profiles of γ-irradiated polyethylene

Asymmetric line profiles of 002 X-ray reflection diffracted from polyethylene have been analyzed. It is found that the asymmetry of the line profile is evidence for a specific correlation between the size and the lattice spacing in the crystallites. This means that the asymmetrical profile consists of two symmetrical profiles whose centroid positions and widths differ from each other. Application to γ-irradiated polyethylene reveals that degradation of crystallites occurs from the surface and that smaller crystallites with larger lattice spacing disappear more quickly when degraded by γ-irradiation. (author)