TNP Synthese

In my endless hunger for new experiences in the field of energetic
materials,
I tried to make some trinitrophenol, also known as picric acid.

So I went out of my cosey little house, and got me 20 aspirines,
(each
containing 0.5 grams of acetylsalicylic acid) from the good people at bayer.

Once I got home I purified these using warm acetone.

Since many
people asked me:"How do you purify aspirines with warm acetone?" Here's how:

Heat up acetone to around 50°C, while it's heating, crush the aspirine
tablets
and add them to the acetone. Stir well so all that remain is a very
fine dust
on the bottom of your beaker. Then filter with a coffee filter,
and save the liquid.
Rinse the filter with a little more warm acetone. Now
let all the acetone evaporate.
What is left should be nice white pure
acetylsalicylic acid crystals.

Now what would you need for making
this into TNP ?
- 140 ml of >95% H2SO4 (sulfuric acid)
- 20 grams of
KNO3 (potassium nitrate)
- 10 grams of acetylsalicylic acid (ASA)

First dissolve the ASA in hot sulfuric acid, then add the KNO3. You
might want to go
easy on the addition of KNO3, because this tends to heat
the mixture quite a bit.
I don't think there is risk for an explosion when
the TNP is in solution, but I don't recommend you try to find out!!
And
definately don't complain with me when it blows up in your face, leaving you
bleeding and full of acid (ouch).

Anyway, once the KNO3 is all added to the acid, you let is
cool down nice and easy,
not applying extra cooling or anything, and give it
an occasional stir,
so gasses can escape the liquid. (wich should be nice
red by now)

Now dump this red liquid (when at lower temperature) in 0.5
liter of ice water.
You'll immedialty notice the change if you're not
colorblind, it turns nice yellow !!
Leave it a bit, with good stirring, so
all the yellow TNP comes out,
but while keeping the mixture as cold as
possible.

Then filter this mixture (normal filter paper should be okay
when you used enough of ice-water).

Don't forget to rinse with as cold
as possible water (barely liquid)
Not too much, but make sure most of the
H2SO4 is rinsed off.

Now you can sqeeze this out, and put it in the sun for drying,

which is going to be very difficult if there is still some sulfuric acid
present.

From 10 grams of ASA, I got 10 grams of TNP, and I did it in 2
steps,
so you should be able to get some more out of it

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