Wednesday, November 23, 2016

Dr T Midgley... chemist

Thomas Midgley was a renowned chemist and inventor who held over 100 patents in his lifetime, but he’s most notorious for two chemicals which wreaked untold havoc on the environment: leaded gasoline and Freon. If that wasn't enough to pollute the world, he also pioneered CFCs, which led to all the plastics that float in the oceans, and styrofoam pellets that don't ever break down.

Doctor Thomas Midgley Jr., an American mechanical engineer and chemist. He was a key figure in a team of chemists, led by Charles F. Kettering, that developed the tetraethyllead (TEL) additive to gasoline as well as some of the first chlorofluorocarbons (CFCs).

Decades later, Midgley's two foremost inventions, leaded gasoline and chlorofluorocarbons, would be globally banned after wreaking havoc on both public health and the world environment.

In the late 1910's, working as a chemist at Dayton Research Laboratories, a subsidiary of General Motors, Midgley tackled the issue of "engine knocking," a problem that plagued old automotives. Fuel would ignite too rapidly, and outside the areas of normal combustion in the engine. This would prompt a temporary loss of power, marked by a disconcerting "pinging" sound.

Midgley discovered that adding a compound called tetraethyllead to fuel could greatly boost its octane rating, an indication of how much compression fuel can withstand before detonating. The additive effectively eliminated the problem of engine knocking, an accomplishment that garnered him the prestigious Nichols Medal from the American Chemical Society. But it simultaneously introduced a new problem: lead.

In the early 1930's, Midgley sought to create a new, innocuous refrigerant for air conditioners and refrigerators. At the time, those machines used toxic and flammable compounds like ammonia, chloromethane, propane, and sulfur dioxide. Consulting his trusty periodic table, Midgley identified a new compound, dichlorodifluoromethane -- more commonly known as freon -- in just a matter of days. It caught on in a similarly hasty fashion. Apparently safe, non-flammable, and non-toxic, the gas appeared in almost all refrigerators within only a few years. It also found its way into aerosol deodorants and pretty much any sort of consumer spray device.

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