Polythene – the accidental invention

Most common plastic objects, from water pipes to food packaging and hardhats, are forms of polythene. The 80m tonnes of the stuff that is made each year is the result of two accidental discoveries.The first occurred in 1898 when German chemist Hans von Pechmann, while investigating something quite different, noticed a waxy substance at the bottom of his tubes. Along with his colleagues he investigated and discovered that it was made up of very long molecular chains which they termed polymethylene. The method they used to make their plastic wasn’t particularly practical, so much like the penicillin story, no progress was made for some considerable time.

Then in 1933 an entirely different method for making the plastic was discovered by chemists at, the now defunct chemical company, ICI. They were working on high-pressure reactions and noticed the same waxy substance as von Pechmann. At first they failed to reproduce the effect until they noticed that in the original reaction oxygen had leaked into the system. Two years later ICI had turned this serendipitous discovery into a practical method for producing the common plastic that’s almost certainly within easy reach of you now.