Sciencemadness Discussion Board

required density for detonation of nitrocellulose

prometheus1970 - 21-6-2011 at 07:19

If I were to want to detonate nitrocellulose (Ag2C2/AgNO3 as primary) would the nc need to be at its optimal density of 1.2g/cc? or will it detonate if just packed snugly? Obviously the higher the density of the nc, the better...better shock propogation, etc., but does it need to be at the level of more than a gram per cc?

IndependentBoffin - 21-6-2011 at 07:45

Higher density is not necessarily better. You need porosity to get hot spots in the NC for sensitivity to initiation and shock propagation.

If you want your NC at the highest possible density but still sensitive to initiation and self-sustaining propagation, you could look at adding micro glass beads to it.

Glass is great as a hot spot generator because it has a high melting point and hardness (hence when glass rubs against each other you get high local temperatures, instead of melting-point limited temperatures).

Hollow glass beads add double the fun because they can be shock compressed leading to further hotspot generation by adiabatic compression.

http://www.unibrite.com/GLB-COATED.htm

Try 5 or 10 micron ones :)

The WiZard is In - 21-6-2011 at 08:08

Quote: Originally posted by prometheus1970  
If I were to want to detonate nitrocellulose (Ag2C2/AgNO3 as primary) would the nc need to be at its optimal density of 1.2g/cc? or will it detonate if just packed snugly? Obviously the higher the density of the nc, the better...better shock propogation, etc., but does it need to be at the level of more than a gram per cc?

Counter Intuitive it do be — wet NC works better.

The British used compressed cellulose nitrate for demolition
charges into WW II.

I The Analogue Guy own an original copy of this —
you can DL yours from Google.com/books


Compressed gun cotton for military use: translated from the German ...
Max von Förster, John Philip Wisser - 1886 - 164 pages
TRANSLATED FROM THE GERMAN of MAX VON FORSTER
WITH AN INTRODUCTION MODERN GUN COTTON,
MANUFACTURE, PROPERTIES AND ANALYSIS.
BY Lieut JOHN P. WISSER, USA NEW YORK).
VAN NOSTRAND, PUBLISHER, 23 Murray and
27 Warren Streets. 1886. ...

Blasty - 21-6-2011 at 18:52

It would appear from the passages I quoted a while back in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=13283&...

that nitrocellulose is rather tricky to detonate. It seems to require reduction to a more dense form, not the bulky form it has when first nitrated (if using cotton balls, for example.) Anyone have any good ideas about how could this be done without the specialized machinery the "pros" use to reduce it to that state (they "pulp" the nitrocellulose)? Perhaps putting the nitrated cellulose in a powerful blender with some amount of water or something along those lines?

Bot0nist - 21-6-2011 at 20:01

I believe adding a bit of acetone, casting the gel into confinement, vibrating it to reduce bubbles and drying the cellulose nitrate will shoot if a good initiator is impressed into it. The air bubbles may be beneficial for propagation though according to IB's mention of adiabatic compression. I have heard of such things like pebbles, glass beads, and silica-gel beads to sensitize NH<sub>4</sub>NO<sub>3</sub> compositions. It would be worth some experiments to see its effectiveness with cellulose nitrate.

[Edited on 22-6-2011 by Bot0nist]