polyethylene

polyethylene (pŏl'ēĕth`əlēn), widely used plastic. It is a polymer of ethylene, CH₂=CH₂, having the formula (-CH₂-CH₂-)_n, and is produced at high pressures and temperatures in the presence of any one of several catalysts, depending on the desired properties for the finished product. Polyethylene is resistant to water, acids, alkalies, and most solvents. Its many applications include films or sheets for packaging, shower curtains, unbreakable bottles, pipes, pails, drinking glasses, and insulation for wire and cable.

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polyethylene (PE)

Any of the polymers of ethylene, the largest class of plastics. Its simple basic structure, of ethylene monomers, can be linear (high-density and ultrahigh-molecular-weight polyethylene; HDPE and UHMWPE, respectively) or branched to a greater or lesser degree (low-density and linear low-density polyethylene; LDPE and LLDPE, respectively). The branched polyethylenes have similar structural characteristics (e.g., low crystalline content), properties (high flexibility), and uses (packaging film, plastic bags, mulch, insulation, squeeze bottles, toys, and housewares). HDPE has a dense, highly crystalline structure of high strength and moderate stiffness; uses include beverage bottles, liquid detergent jugs, crates, barrels, and luggage. UHMWPE is made with molecular weights 6–12 times that of HDPE; it can be spun and stretched into stiff, highly crystalline fibres with a tensile strength many times that of steel; uses include bulletproof vests.