ABSTRACT
The driving force behind the formation of crystals, which are structures having a long-range periodic order, is the lowering in free energy that accompanies the process of crystallization. In addition to temperature, the extent of crystallization also depends on factors such as the applied stress during processing, which tends to align polymer chains in the stress direction. The combined process of nucleation and growth is the same, regardless of whether the crystallization behavior being observed is that of molten metals or molten polymers. If one of the components is crystallizable, the presence of the other component can influence the nature, rate, extent, and temperature range of crystallization. V. M. Nadkarni and J. P. Jog have summarized the crystallization behavior of commonly encountered crystalline/amorphous as well as crystalline/crystalline polymer blend systems. In practical polymer processing operations, crystallization takes place from oriented polymers under stress, and events arise that cannot be explained in a quantitative manner.
