overload - 10-10-2011 at 23:00
I have been asking questions and thinking about why we always apply a vacuum when distilling things like free base amines and stuff like that. At
first I thought it was only to lower the BP to prevent decomposition. Now I have learned that not only does that apply but also the air within the
distillation apparatus contains about 300mg of oxygen in a 14/20 distillation set up. I've read that when amines are heated to high temperature they
react with oxygen in the atmosphere creating unwanted side products. This pretty much defeats the purpose of distilling amines without a vacuum or a
nitrogen purge / stream. I was thinking that It may be possible to prevent some by products by connecting an addition funnel to the setup and then
attaching a balloon to the gas outlet. You then open the addition funnel and suck out the air (with your mouth.. don't inhale) then close the funnel.
Do it again and again until the balloon is almost getting sucked into the set up. Commence distillation. This should cut back on the amount of oxygen
but the only problem is if the balloon starts to fill up. I don't see why it would if things go accordingly. If the ballon does start to fill up just
release the pressure through the addition funnel.
[Edited on 11-10-2011 by overload]