Two British research chemists miss an important detail… and make polyethylene.
Reginald Gibson and Eric Fawcett worked at Imperial Chemical Industries’ research laboratory at Winnington, Cheshire. When they attempted to react ethylene and benzaldehyde under high pressure, they produced a waxy lump of what the British call polythene. The experiment could not be successfully repeated; unbeknownst to the researchers, oxygen had leaked into their apparatus and catalyzed the reaction. Using better equipment two years later, ICI scientists M.W. Perrin and J.C. Swallow detected a leak. It took several months before they figured out that it was trace oxygen in the ethylene that played the key role in the reaction.
American chemist Carl Marvel actually made polyethylene by a different method before the ICI team, in the early 1930s. He had just ignored it, because “nobody thought polyethylene was good for anything.” ICI, however, had plenty of ideas for it. The chemical conglomerate obtained its first patents in 1936 and quietly put the new plastic into production in 1938.
Polyethylene was a military secret during World War II. It was used to insulate cables on newly developed radar devices. Large-scale commercial polyethylene production began after the war, creating a plethora of plastic kitchenware, toys, containers, and packaging. Polyethylene achieved wide use because of its versatility and low cost. It now competes with other plastics like polyfluoroethylene and polypropylene. Low-density polyethylene (LDPE) has lots of branched polymer chains, which make it more flexible for use in plastic bags, films, and packaging materials. High-density polyethylene (HDPE) has long, straight polymer chains, which make it more durable for use in containers, plumbing, and other parts and fittings.
Too much of all this plastic stuff, alas, finds its way into the oceans as floating pollution.—RA