Structure refinement of high-density polyehylene using x-ray powder diffraction data and the rietveld method

摘要

A full structure analysis of a completely crystallized sample of high-density polyehylene (HDPE) has been achieved using x-ray powder diffraction data collected on a labortory-based powder diffractometer. The structure refinement is performed using the Rietveld method and includes refinement of the carbon and hydrogen atomic positions and temperature factors. The C-C and C-H bond distances and the C-C-C bond angle along the polyethylene chain have been calculated from the refined atomic positions and are in very good agreement with previous experimental and modelling determinations. Evaluations of the pseudo-Voigt profile parameters for Lorentzian strain broadening and the Scherrer coefficient for Gaussian broadening yield reasonable values for microstrain and particle size for this sample.