Three Discoveries by Chance: the Incredible Story of the Most Important Synthetic Material

The most important synthetic material in the world was invented by accident. It seems that in the field of plastics this is not all that unusual: more or less every major variant has been discovered this way. But what distinguishes the most important synthetic material in the world is that it was invented by accident not once or twice, but three times.

The first accidental discovery occurred in 1894, when a German chemist, Hans von Pechmann, was experimenting with an explosive gas, diazomethane. He discovered that it decomposed into a white powder of hydrogen and carbon, which he called «polymethylene». Then he forgot about it.

In 1930, two researchers at the University of Illinois were tinkering with organic arsenic compounds. From their experiments emerged a strange white residue similar to wax. «This solid», they wrote, «has not been studied further». End of the story.

The last discovery — the decisive one — took place in March 1933 in the Northwich laboratories of ICI, the British chemical giant. Eric Fawcett and Reginald Gibson were working on the chemical transformations that occur under high pressure

Tre scoperte per caso: la storia incredibile del materiale sintetico più importante

One day they carried out some experiments with ethylene. By combining ethylene with another gas, benzaldehyde, at a pressure of fourteen hundred atmospheres, they obtained a «white solid similar to wax». They had (re)discovered polymethylene, which they renamed «polyethylene», or also «polythene».

There are many types of plastic, but few are as useful and versatile as polyethylene, which can be processed to obtain varieties with extremely high molecular weight, more rigid than steel, or alternatively a low-density material soft like wax. Its incredible ductility means that it does not break, but tends to stretch. Waterproof and durable, it withstands heat slightly beyond the boiling point of water and is recyclable; it can be woven into fibers so strong that they repel projectiles, and the fact that it is not a good conductor makes it a perfect electrical insulator.

The era of international communications had just begun, and everywhere there were copper wires for telephone and electrical lines that required protective and insulating layers. The material used for this purpose was gutta-percha, a natural latex obtained from the sap of a tree in Malaysia. The cables were insulated with this substance and then wrapped in a hard lead coating. But because of production times and costs, it was impossible to keep up with the demand for wiring.

In theory, polyethylene was the perfect substitute. The only problem was producing it. A couple of days after their discovery, Fawcett and Gibson returned to the laboratory trying to replicate the experiment. A huge explosion destroyed their equipment, but they kept insisting, even though explosions occurred each time, until, after the umpteenth fire, they suspended tests with ethylene while waiting to receive more robust equipment.

The trick was to build the reaction chamber with a type of steel that was not too brittle and very ductile, sufficiently flexible to withstand the extremely high pressure required for the reaction.