Today in History – March 27, 1933 – Polyethylene is discovered. Polythene is also known as polyethene or polyethylene. It was discovered in 1933 by Reginald Gibson and Eric Fawcett, two scientists working at ICI’s research laboratory at Winnington, Northwich, who accidentally discovered the white, waxy solid while attempting to react ethylene with benzaldehyde in an autoclave. The first patents for polythene were registered in 1936, and a year later the first practical use for the material, as a film, was discovered. Polythene was used as an insulating material for radar cables during World War II, and the substance was a closely guarded secret. After the war it began to be produced commercially and used to make a wide range of products. These objects illustrate the variety of household items in everyday use that are made from polythene.
Polyethylene has the advantages of excellent chemical, electrical, and moisture-vapor resistance. It’s principal disadvantage is poor mechanical strength. It is widely used in packaging films and sheets, containeres, wire cable insulation, pipe, linings, coatings, toys, and housewares.
Polyethylene can be manufactured as a high-density or low-density product. High density polyethylene, manufactured by a low-pressure process, is commonly used for blow-molded bottles and other containers, as well as injection-molded articles and pipe. Low density polyethylene, manufactured by a high-pressure process, is used primarily for films. U.S. manufacturers of polyethylene have included Union Carbide (now Dow Chemical), Dow, DuPont, and Conoco-Phillips.
For more information see the Engineering Pathway’s educational resources on polyethylene and other polymers. For related curricular resources, visit the Chemical, Biochemical, Biomolecular Engineering disciplinary communities. Further information and flow charts for the high-pressure and low-pressure processes are available in Shreve’s Chemical Process Industries, Fifth Edition, by George T. Austin, McGraw-Hill, New York, 1984.