ABSTRACT
Solid polymers can occur in the amorphous or crystalline state. Polymers in the amorphous state are characterized by a disordered arrangement of the macromolecular chains, which adopt conformations corresponding to statistical coils. The crystalline state is characterized by a long-range threedimensional order (order extending to distances of hundreds or thousands
of times the molecular size of the repeating unit). The macromolecular chains in this state adopt fixed conformations such as planar zigzag, or helical. These chains are aligned parallel to each other, forming a compact packing that gives rise to a three-dimensional order. The differences in arrangement of polymer chains in the crystalline and amorphous states are schematically illustrated in Figure 2.1.
