Crystallinity of Polymer Plastics

 Polymeric materials have a wide range of applications in every aspect of modern society, from packaging materials to aerospace engineering, and possess different properties for different purposes. The Degree of Crystallinity (DOC) is a key index affecting the properties of polymeric materials, and changes in crystallinity influence various characteristics such as mechanical properties, thermal properties, density, and optical properties of polymers. Therefore, controlling the crystallinity of polymeric materials is an important factor in materials engineering.

In general, methods for measuring crystallinity include density methods, calorimetry, NMR, IR, and XRD. Among these, X-ray diffraction is considered a more comprehensive and intuitive technique for analyzing polymer structure, providing clearer data and being more widely used. Common methods for determining the crystallinity of polymers using X-ray diffraction include mapping, regression lines, the Ruland method, and partial peak fitting of X-ray diffraction curves. Additionally, X-ray diffraction can also be used to analyze the polymorphism, grain size, and structure of polymeric materials.