Abstract
Crystallization in structure of high density polyethylene (HDPE) was investigated by scanning electron spectroscopy (SEM) that appeared as gel formation (unmelted spot of polymer) in film matrix for both compared films of HDPE i.e., it directly affect the mechanical properties (tear strength, elongation, and tensile strength at break). At the same time, we determined the degree of crystallinity measured by X-ray diffraction (XRD) which showed that the crystallinity exceeded more than 45% in HDPE. The XRD is associated with partial alignment of their molecular side chains.