Tuesday, March 15, 2016

Polyoxybenzylmethylenglycolanhydride


We should address Bakelite one more time, as it's connected to our business at both ends. the genesis of that polymer was the expense of the increasingly scarce imported shellac and in application it appeared in all manner of electronics including radio. Where does the name come from?  Well Bakelite is easier to pronounce than polyoxybenzylmethylenglycolanhydride.

Actually it's inventor, chemist Leo Baekeland named it after himself in 1907.  Shellac (as you know) is made from a resin secreted by the lac bug. Kerria lacca is the Latinate name usually thrown around, but actually the species Kerria yunnanensis is farmed just as often for those highly useful secretions. (Also note it's technically a bug, and not a beetle though it looks like one to me.)  The resin was harvested by scraping the hardened lac deposits on trees by the insects. It was a labor intensive manual process begging for a better i.e. cheaper alternative.

Enter Mr. Baekeland. Compared to modern plastics, Bakelite is easy enough to make. It is formed via a condensation reaction of phenol with formaldehyde. These were not new ingredients. Phenol was first discovered in 1834 by Friedlieb Ferdinand Runge. Auguste Laurent should get some credit for rendering a pure form in 1841. Karl Reichenbach is also often cited as having discovered phenol but this may have been independent.  It was quickly discovered to be an antiseptic, but it was also used by the Nazi's for euthanasia.  Formaldehyde is even older. It was first reported in 1859 by the Russian chemist Aleksandr Butlerov, then again in 1869 by August Wilhelm von Hofmann

Despite that, Bakelite wasn't the first plastic. Synthetic rubber was the holy grail of chemistry for most of a century.  In 1860 Greville Williams distilled isoprene from natural rubber.  By 1880, French chemist Gustave Bouchardat was deriving rubber-like substances from isoprene. Parkesine was patented by Alexander Parkes in 1856. It was made from cellulose treated with nitric acid. In 1893 Auguste Trillat learned how to make a hard plastic he marketed as "Galalith". It was made from casein (a milk protein) treated with formaldehyde. Apparently Bakelite topped them all.

No comments:

Post a Comment