Polyethylene consists of nonpolar, saturated, high molecular weight hydrocarbons. Therefore, its chemical behavior is similar to paraffin. The individual macromolecules are not covalently linked. Because of their symmetric molecular structure, they tend to crystallize; overall polyethylene is partially crystalline. Higher crystallinity increase density and mechanical and chemical stability.
Most LDPE, MDPE, and HDPE grades have excellent chemical resistance, meaning they are not attacked by strong acids or strong bases, and are resistant to gentle oxidants and reducing agents. Crystalline samples do not dissolve at room temperature. Polyethylene (other than cross-linked polyethylene) usually can be dissolved at elevated temperatures in aromatic hydrocarbons such as toluene or xylene, or in chlorinated solvents such as trichloroethane or trichlorobenzene.
Polyethylene absorbs almost no water. The gas and water vapor permeability (only polar gases) is lower than for most plastics; oxygen, carbon dioxide and flavorings on the other hand can pass it easily.
PE can become brittle when exposed to sunlight, carbon black is usually used as a UV stabilizer.
Polyethylene burns slowly with a blue flame having a yellow tip and gives off an odor of paraffin (similar to candle flame). The material continues burning on removal of the flame source and produces a drip.
Colour : White
Appearance : Flake
viscosity mPa. S : 50±30
Bulk Density g/l : 0.93±0.02
Melting Point C : 100+10
Volatile content @ 150 ℃ : 2-3%
R&B Softening point ℃ : 100±5