One-dimensional models for small-angle X-ray diffraction from crystalline polymers. I. General model

The relationship between a one-dimensional model for predicting small-angle X-ray scattering from crystalline polymers and a three-dimensional structure containing a one-dimensional periodicity is discussed. The basic features of previous models are reviewed. Based on the approach of Hosemann for a simple two-phase system, a model is formulated in which the density variation within the crystalline regions is described by an arbitrary function ξ(y).