ABSTRACT
X-ray diffraction is an extremely valuable technique for investigating polymer structure and morphology. X-ray diffraction is the traditional method of crystallographic structure determination, and standard techniques and analysis procedures can be used in the study of crystalline polymers. An information that can be obtained by X-ray diffraction includes crystal size and perfection, the 'long period' in lamellar polymers, the crystallinity, the degree of preferred orientation in polycrystalline samples, and, with the help of computer modelling, the conformation of chains in amorphous polymers. The chapter examines the characteristics of X-ray diffraction when a monoenergetic parallel X-ray beam impinges on a crystal. Wide angle X-ray diffraction is sometimes used for the accurate measurement of selected lattice spacing in a crystalline polymer in order to determine the strain in the crystal in the corresponding direction. In rotation and oscillation methods a single crystal sample is mounted with a prominent symmetry axis vertical and bombarded with a narrow horizontal beam of X-rays.
