Analysis of x-ray diffraction scans of poorly crystallized semicrystalline polymers

摘要

X-ray diffraction (XRD) scans of many semicrostaline polymers, in which noncrystalline (amorphous) phases with varying degrees of order coexist with more than one crystalline phases, are usually not well resolved. Resolution of such data can be enhanced by deconvolving the effect of size broadenign using maximum entropy methods. The use of resolution-enhanced XRD scans for studying the order in the noncrystalline (amorphous) domains and for studying small differences in the crystalline regions in poorly crystallized polymers is illustrated with examples from polymaides and polyesters. Crystallinity in poorly crystallized polymers is determined using an amorphous template obtained by analyzing highly crystalline polymers. The degree of order in the noncrystaline regions is evaluated from the changes in the shape and the position of the amorphous scattering. It is suggested that these procedures can be a part of the documentation of laboratory procedures required for ISO (International Organization for Standards) certification.