crystalline polymer

In chemistry, a crystalline polymer is a polymer that contains ordered regions called crystallites, where molecules pack together in a regular arrangement. This ordered structure, also known as semicrystalline morphology, contrasts with amorphous polymers where molecules are randomly oriented. Linear polymers, due to their regular structure, are more likely to be semicrystalline.1

The presence of crystallites makes semicrystalline polymers tough and often opaque, as they scatter light. Crystallinity can be increased by stretching the polymer, a process called drawing, which aligns the molecules. When heated, semicrystalline polymers can melt and become molten, allowing them to be spun into fibers or molded into shapes, classifying them as thermoplastic polymers.12