Defects and Disorder in Polymer Crystals

The main characteristics of polymeric materials is that, unlike other crystalline materials, they are never completely crystalline but are semicrystalline and composed of crystals embedded into an amorphous phase, producing a highly interconnected network. The classification of the defects in crystals based on the definition of distortions of first and second kinds is useful and covers some of the possible types of disorder that may be present in crystals of polymers. A more general classification of the structural disorder in polymer crystals is based on the analysis of the effect of every kind of disorder on the X-ray diffraction and electron diffraction patterns of polymers. Different types of structural disorder affect differently the X-ray diffraction pattern of polymer crystals.