Liquids X-ray scattering

Most polymers are partially crystalline. The degree of crystallinity of polymers may, however, range very widely from 0 percent for noncrystalhzable polymers, through intermediate crystallinities, up to nearly 100 percent for polytetra uoroethylene and linear polyethylene. A direct evidence of the crystallinity in polymers is obtained from x-ray dilfraction studies. The x-ray patterns of many crystalline polymers show both sharp features characteristic of ordered regions (called crystallites) and diffuse features characteristic of a molecularly disordered phase like liquids. X-ray scattering and electron microscopy have shown that the crystallites are made up of lamellae which, in turn, are built-up of folded polymer chains as explained below. 

---