Sciencemadness Discussion Board

Plasticized ETN vs PETN

KiT1212 - 27-9-2019 at 21:25

I've been wondering this for a while but wouldn't plasticized ETN preform better in therms of brisance commpared to PETN plasticized to the same degree due to the better oxygen balance? (eg 12% inerts)

ETN OB: 5.3

PETN OB: -10.1

underground - 28-9-2019 at 13:10

There is big difference between fuel in molecule and fuel in mixture. High density pressed PETN will outperform any ETN plastic with even perfect OB



[Edited on 28-9-2019 by underground]

KiT1212 - 28-9-2019 at 18:59

Well yeah at max density PETN outperforms RDX.
But plasticized i dont know what density it can reach.
My ETN mix is at 1.55g/cm3

Id wish i had piezo sensors to test out det velocity

wessonsmith - 29-9-2019 at 07:49

Quote: Originally posted by KiT1212  
I've been wondering this for a while but wouldn't plasticized ETN preform better in therms of brisance commpared to PETN plasticized to the same degree due to the better oxygen balance? (eg 12% inerts)

ETN OB: 5.3

PETN OB: -10.1


Here is what people forget about when comparing HE. They always want to compare the performance figures of said explosives at their max densities:

PETN @ 1.77 g/cm³
RDX @ 1.82 g/cm³
HMX @ 1.91 g/cm³
CL-20 @ 2.04 g/cm³

The thing is, in practice, ESPECIALLY backyard chemists like ourselves, the densities of the explosives we will be using, plastic explosives, in our detonators, etc. will be between 1.45 - 1.72 g/cm³. The power difference between PETN and ETN at a similar density is less than 1%. When you put the positive OB of ETN into a plastic fuel binder and compare that to a PETN version at a similar density, ETN will win hands down.

Where things shine for ETN is in thermobaric mixtures based on a plastic fuel binder like HTPB. The difference is night and day even when compared to HMX. An HMX based thermobaric explosive mixture requires 10% of the total mixture to be made up of Ammonium Perchlorate. The ETN version doesn't require AP, so you are comparing two thermobaric compositions, ETN version that is 55% HE and the HMX version, which is 45% HE. That's 22% more HE in the ETN version, so ETN wins even though HMX is 14% more powerful than ETN.

Now if you have the proper equipment you can press pellets of HMX mixed with 1.5% of Viton or even Stearic Acid and you will have an explosive mixture considerably more powerful than melt-cast ETN but since I don't have that equipment, I'll stick with ETN.