Sciencemadness Discussion Board

How come polyethylenimine isn't highly explosive?

Osiris - 30-5-2020 at 03:30

It is my understanding that an abundance of nitrogen bonds make something explosive.



I understand that in order for something to explosive, it has to actually be combustible. Also, I suppose I could entertain the thought that a molecule of a certain combination, if combusted, would have a lot of opposing
forces, resulting in a net force of ~0. I'm not a chemist, so this just guesswork.

Thanks!

unionised - 30-5-2020 at 04:34

At last in part, because it has twice as much C as N (So, it really hasn't got much nitrogen in it) and none of the bonds to the nitrogen are multiple bonds or bonds to oxygen.

Dr.Bob - 30-5-2020 at 04:42

The nitrogen in an explosive has to be present in a total stochaimetry that generates a lot of gas (and energy) from a solid or liquid, without external oxidants. Thus trinitroglycerin can break down energetically, and the oxygen from the nitrates can oxidize most of the carbon to CO2 and water, leaving only nitrogen left, all gases. But in amines, like polyethylenimine, there is no oxidant present, so there is no oxidant to provide some energy to drive the reaction, or stored energy to release upon the bonds breaking. For a reaction to occur, the energy of the products must be less than the starting material, and the released energy can then provide an exotherm. For compounds to be unstable, there normally needs to be more nitrogen and oxygen atoms than carbons, eg tetrazole, azides, or nitrates. There are also compounds that have ring strain or other issues that help add more pent up energy to the starting materials. That is why octanitrocubane is so great.

Osiris - 30-5-2020 at 05:06

Thanks guys.