GENERAL PROCEDURE FOR EVALUATING AMORPHOUS SCATTERING AND CRYSTALLINITY FROM X-RAY-DIFFRACTION SCANS OF SEMICRYSTALLINE POLYMERS

The separation of amorphous and crystalline contributions in diffraction and spectroscopic data is a necessary step in the study of the structure of the less-ordered regions and in the calculation of crystallinity of a semicrystalline polymer. We suggest here that the diffraction pattern of a polymer with a high degree of crystalline order be fitted with easily resolvable crystalline peaks, and the intensity not attributable to the crystalline peaks be regarded as amorphous scattering. This amorphous halo can be used as a template in analysing the diffraction patterns of less-crystalline samples, and to follow changes in the amorphous regions. This method is most useful for polymers for which a completely amorphous sample cannot be easily prepared, and in the analysis of poorly crystallized polymers. The method is illustrated with examples from several polymers. © 1990.