Sciencemadness Discussion Board

Menthol

Teen Chemist - 26-9-2012 at 13:21

I searched menthol and there is a suprising lack of mention. I was shocked because it is such an interesting molecule. It has so many cool properties and uses. I just felt it needed its own thread.

Bot0nist - 26-9-2012 at 14:30

I agree, it is interesting, but to start a discussion you need to bring more to the table in your post. Include some synthesis refrences and experiments, some extraction and isolation information, maybe even a brief description and some applications you find interesting.

Check out the Forum Guidelines as they will help you craft a post that will be better recieved and avoid getting on any of the mods/members nerves. For instance, without references, this thread will likely be place in beginings.

Good luck,
TheBot.

Teen Chemist - 26-9-2012 at 16:58

How about this, I am currently trying to extract menthol from a pain reliever called Biofreeze by boiling the jel in water then cooling it to recrystalize.

[Edited on 27-9-2012 by Teen Chemist]

Waffles SS - 27-9-2012 at 00:48

Menthol Topic:
http://www.sciencemadness.org/talk/viewthread.php?tid=16366#...

[Edited on 27-9-2012 by Waffles SS]

triplepoint - 27-9-2012 at 02:35

Quote: Originally posted by Teen Chemist  
I am currently trying to extract menthol from a pain reliever called Biofreeze by boiling the jel in water then cooling it to recrystalize.


According to the MSDS, Biofreeze is 15 - 40% Isopropyl Alcohol, 3%-7% L-Menthol and 1%-5% glycerin. Presumably, the remainder is water. The isopropyl alcohol forms an azeotrope with a bp of 80.37ºC, so that should be the first fraction to come off. Next is the isopropyl alcohol itself, with a bp of 82.5ºC. At that point, you will be left with water, menthol, and glycerine. L-menthol freezes at 41-43ºC, while glycerine does not freeze until 18.17ºC, so you should be able to crystallize it out of the solution. (Of course, these numbers are altered a little by the fact that the substances are mixed together, but the MPs and BPs are separated enough that it should not change the outcome.)

I also urge you to take precautions when boiling off IPA around an open flame.

Teen Chemist - 27-9-2012 at 11:15

I use a hot plate to heat most of the things that need heating.

Hexavalent - 27-9-2012 at 11:40

What would be interesting to see is if someone could oxidize it to menthone (the ketone) and then further to break open the ring.