Splinky - 29-3-2008 at 12:27
I just tried to nitrate about 1.7 grams of cellulose in the form of cotton balls with the method used on brainfevers site. I dissolved 25 grams of
KNO3 into 30 ml of drain opener sulfuric acid, once the saltpeter had dissolved and the mix stopped warming up, I added the cotton and let it sit for
about ten minutes. When I fished the balls out I noticed that there was a lot of solidification in the mix and had to dig through the sludge like
mixture to get at the potential cellulose nitrate. They quickly sank into the water that I put them in and were solid in the center when I did.
Is this just the potassium sulfate that was left over from the KNO3+H2SO4 -> HNO3? I will neutralize and dry the wads so I can test them tomorrow,
but I wanted to ask if this was normal.
Zinc - 29-3-2008 at 13:03
I think that it is normal. The same thing happens to me when I use sodium nitrate/H2SO4. Use ammonium nitrate instead of potassium nitrate if you want
to avoid that.
Splinky - 29-3-2008 at 13:28
I just dried some of it partially, and a few strands took flame with much more vigor than regular damp cotton, so I guess it is okay. I think I'll
just wait until I get some real glass ware (did this in a glass seasoning jar) before I try again.
Edit: Now today it doesn't seem to be acting like what I have seen of cellulose nitrate, it fizzles for a bit before making a small poof. Is it
possible to have only partially nitrated it? I also think that I got a hint of sulfur when I lit a couple pieces of it, but I probably just didn't
wash it well enough to get out all of the potassium sulfate.
[Edited on 30-3-2008 by Splinky]
ScienceGeek - 30-3-2008 at 07:34
Did you completely submerge the cotton in the nitrating solution? If not, it would only be partially nitrated. If you did submerge it completely, I
don't see how it could only be partially nitrated...
ordenblitz - 30-3-2008 at 09:03
The thing that makes a lot of difference but most first timers overlook is dehydrating your cotton before nitration. Extra water is your enemy so I
would even go as far as to bake out your nitrate before mixing as well.
ScienceGeek - 30-3-2008 at 09:40
That's true, but in my experience insignificant as long as concentrated sulfuric acid is used.
Splinky - 30-3-2008 at 09:50
Yes, it was completely submerged. However I used Rooto and did not dehydrate the cotton or KNO3 beforehand, so the extra water route might be the
explanation.
ScienceGeek - 30-3-2008 at 09:57
But then the cotton should be partially nitrated as a whole, and not some part of the cotton more nitrated than another part...strange results you've
gotten there!
Splinky - 30-3-2008 at 11:13
Maybe the solidification of the sulfate prevented some of the cotton from getting into contact with acid. The whole mass is slightly yellowed,
probably from the dye in the acid.
ScienceGeek - 30-3-2008 at 12:22
The cotton becomes slightly yellow either way. That is due to the Nitrogen groups in the cellulose and also due to Nitrogen Dioxide. But your
explanation seems plausible!