On this day in 1933, polyethylene was discovered–by accident–by British scientists Reginald Gibson and Eric William Fawcett. It is one of the first plastics to come into common use.
Familiar to lay people in dozens of iterations, from plastic bags to piping, polyethylene is the most widely used plastic in the world. In fact, polyethylene was first synthesized in 1898 by the German chemist Hans von Pechmann. While heating chemical compound diazomethane, Pechmann noticed a waxy, white substance was formed. His colleagues recognised it and termed it polymethylene.
Decades later, two scientists working at the British industrial giant Imperial Chemical Industries in Northwich, England, made a similar accidental discovery. They were applying extremely high pressure–up to several hundred atmospheres–to a mixture of ethylene and benzaldehyde when they noticed the same telltale waxy, white material. Because the reaction had been helped along by some oxygen contamination, it took another ICI scientist two years to develop the process into a reproducible high-pressure synthesis for polyethylene. The first patents were registered in 1936. During World War II, polyethylene was used as an insulating material for radar cables–and kept as a closely guarded secret. After the war, it was produced commercially and quickly applied to a wide range of usages.
In real life, we encounter this familiar plastic countless times in a day: it cushions our packages, holds our groceries, seals our lunches tight, forms the toys our tots play with, and shapes the interior of our vehicle dashboard. Divided into high- and low-density polyethylene (based on the manufacturing process), the material is known to be cheap, flexible, durable, and chemically resistant. Besides bags and piping, it’s used to make films, packaging materials, containers, and automotive fittings.
Because of its incredibly widespread usage, environmentalists and scientists are scrutinizing polyethylene’s effect on the environment. The material is based on oil or natural gas and is not biodegradable, earning it censure in some circles. However, it is lightweight (and therefore cheaper to transport), has a long life, and can be produced from renewable sources like sugar cane. The jury is still out on polyethylene’s environmental effect, but the plastic–today the most widely used in the world–is here to stay.