polythene

Polymer of the gas ethene (C₂H₄). It is a tough, white, translucent, waxy thermoplastic (which means it can be repeatedly softened by heating). It is used for packaging, bottles, toys, wood preservation, electric cable, pipes, and tubing.

Polythene is produced in two forms: low-density polythene, made by high-pressure polymerization of ethene gas (the monomer), and high-density polythene, which is made at lower pressure by using catalysts. This form, first made in 1953 by German chemist Karl Ziegler, is more rigid at low temperatures and softer at higher temperatures than the low-density type. Polythene was first made in the 1930s at very high temperatures by ICI.