Explosives are, in a way, like rocket engines: they reached a certain plateau in performance decades ago and haven’t really gotten much better. This is not due to relevant people and organizations not caring to develop new ones; the problem is that there are just so many ways you can stick unstable molecules together in a cost effective manner. Some years ago while working ordnance systems (shaped charges for stage separation, rocket motor initiators, etc.) news came down that a new explosive (Octanitrocubane) was being studied. A *more* powerful explosive. Yay! Then the details came out: it was a *few* percent more powerful than HMX (the current gold standard in high explosive, and it has been since the ’40’s) and was expected to cost more than gold even after the manufacturing processes were worked out. Bah.
But there’s hope of new explodey-sauce:
Ground state structure of high-energy-density polymeric carbon monoxide
Links only to an abstract. But there’s a description HERE. Short form: at least theoretically, if you compress carbon monoxide, and compress it a lot, it seems it’ll form a polymer. It’ll turn into a solid. A solid that should remain a solid when the pressure lets off. But also… a solid with a whole lot of pent-up anger issues:
the team’s search found that the most stable cabon monoxide structure at ambient pressure and temperature would be a polymer, a repeating molecule with a backbone of carbon and oxygen rings called Pna21. But this stuff couldn’t form spontaneously—it needs to be made at high pressures, maybe around ten thousand times higher than sea level pressure. And unlike other carbon monoxide polymers discovered previously, Pna21 would be absolutely explosive, five to ten times more so than the same amount of TNT, thanks to the huge amount of energy it stores.
Five to ten times as explosive as TNT would be damned handy in an explosive. TNT is the standard; HMX has a “relative effectiveness factor” of 1.7. Octanitrocubane is the best at 2.38. But if polymerized carbon monoxide has an R.E. factor of five… that’s about three times better than HMX. Since HMX is what’s used to squeeze plutonium pits to make go “bang,” doing three times better would lead to the potential for smaller, lighter nukes.
Of course, this all depends on whether carbon monoxide really does form a metastable solid explosive at high pressure, and is stable enough to be safe. An explosive that goes off if it rises above, say, fifteen degrees kelvin is less than entirely practical.