Polyethylene, like all plastics, is a polymer-based material, meaning that it is comprised of long chains of identical molecules. The polyethylene molecule specifically is comprised of two double bonded carbon atoms that each has two hydrogen atoms connected to it. Due to its repetitive nature, polyethylene can take many structural forms.
Polyethylene has several desirable engineering characteristics. Polyethylene possesses a crystalline structure and as such does not dissolve at room temperature. Also, polyethylene is extremely chemically resistant, making it perfect for storage of caustic materials and for use as chemical lab ware in research facilities. Polyethylene is also commonly used in situations when metallic materials are not desirable such as when corrosion due to dissimilar metals is an issue.