What is Teflon?

Teflon

Teflon® is the trademark name for a family of fluorinated polymers that includes poly(tetrafluoroethylene), PTFE ([–CF₂–CF₂–]_n).

What are polymers?

PTFE was first made by accident by the American chemist Roy Plunkett when he was working on the development of new non-toxic refrigerants for the chemical company DuPont.

Plunkett used pressurised cylinders of gaseous tetrafluoroethylene (F₂C=CF₂) in his research and on one occasion, on the morning of 6 April 1938, he found that there was no pressure in the cylinder but it weighed the same as when filled with gas. On opening the cylinder, he found a waxy white solid had formed.

PTFE

To his surprise, Plunkett found that the F₂C=CF₂ had polymerized in the bottle to form PTFE. PTFE has some remarkable properties.

It is inert to virtually all chemicals as it contains only strong C–F and C–C bonds, and it is considered the most slippery material in existence because the surface is covered with fluorine atoms that do not interact with atoms in other compounds.

These properties have made PTFE a particularly useful polymer. PTFE tubes hold cables and wires in aircraft and cars, in medicine, it is used in reconstructive and cosmetic facial surgery, and it has become a household name through its use as a coating on non-stick cookware.

Gore-Tex®

Similarly, Bob Gore wasn’t attempting to improve outdoor clothing when he created Gore-Tex®. Working in his father’s Teflon factory in the late 1960s, he was simply trying to make more efficient use of the plastic by stretching it. He found that pulling Teflon filled it with air pockets.

The pockets that appeared in his ‘expanded poly(tetrafluoroethylene) (ePTFE)’ were 700 times larger than a water vapour molecule but 20,000 times smaller than a droplet. Gore reasoned that if you made fabric out of ePTFE, you could block out rain while still venting steamy perspiration, with the added bonus of wind protection.

Since the first jacket was made in 1977, ePTFE has found use in products ranging from heart patches to space suits.

Serendipity

A significant number of other notable scientific discoveries have, like Teflon, been made by chance, or serendipity.

This includes the world’s first artificial sweetener, saccharin (which is 300-400 times sweeter than sugar), discovered by Dr James Schlatter, who, when cleaning lab glassware accidentally tasted a powder on his fingers (he had been making saccharin in connection with an anti-ulcer project). Also, vulcanised rubber, formed when Charles Goodyear accidentally dropped a mixture of rubber, sulfur, and lead onto a hot stove.

More recently, there is Viagra, developed by Pfizer, initially as a new treatment for angina (a heart condition that constricts the vessels that supply the heart with blood). Trials in people were disappointing, but, volunteers started coming back and reporting an unusual side effect!