ABSTRACT
Semicrystalline polymers are those that consist of two or more solid phases, in at least one of which molecular chain segments are organized into a regular threedimensional array, and in one or more other phases chains are disordered. The noncrystalline phases form a continuous matrix in which the crystalline regions are embedded. Most polyolefins are semicrystalline; their specific morphology is governed by molecular characteristics and preparation conditions. Polyethylene is no exception to this rule; it is all but impossible to prepare a solid specimen of polyethylene that is not semicrystalline. All commercial polyethylene products are semicrystalline. The physical properties exhibited by polyethylene products are governed by the relative proportions of the crystalline and noncrystalline phases and their size, shape, orientation, connectivity, etc. with respect to one another.
