Sciencemadness Discussion Board

Plasticizer/Binder

golfpro - 28-9-2013 at 07:22

I had some of this: http://www.wftaylor.com/pdf/msds/720-1%20msds%2012-21-10.pdf

It's a kind of viscous liquid with a sticky, rubbery texture. I plasticized roughly 4 grams of ETN in an approx. 9:1 ratio, after mixing/kneading it very well for consistency, I took little bits at a time for hammer tests, it looked like it all detonated every time. It makes a soft clay w/ fine ETN powder, very workable and hammer sensitive.

It says synthetic rubber, resin w/ solvents, I've never heard of it as a plasticizer/binder but it looks very good, could there be any drawbacks I am not aware of?

Dany - 28-9-2013 at 07:45

golfpro,

The biggest problem when mixing explosive or HEDM with a new, untested binders, plasticizers or adhesive is the chemical compatibility. Some chemical are not compatible with each other so the can react with time or one of the ingredient may induce decomposition in the other component. For a brief section on compatibility check section 5.3 of LLNL Explosives Handbook-Properties of Chemical Explosives and explosive simulants (rev.2-1985), B. Dobratz. Remember not every time you added binder you decrease sensitivity. Many published work mention that increase in sensitivity is observed with some PBX type explosive. The reason of increased sensitivity is the presence of cracks, minute bubble gas (trapped bubble gas or from explosive decomposition) induced with aging or thermal cycling. these voids can act as a potential sites for hot spot formation and thus render the explosive more easy to ignite and this by decreasing the critical pressure of initiation needed for initiation. Also, because you don't have special equipment for pressing your new explosive composition to high density, detonation performance will suffer. So be careful for these aspect with your new explosive composition.

Dany.

golfpro - 28-9-2013 at 07:57

What do you mean pressing a bonded/plasticized material??


Are there any incompatibilities that you see here?

Ral123 - 28-9-2013 at 08:05

Quote: Originally posted by Dany  
golfpro,

The biggest problem when mixing explosive or HEDM with a new, untested binders, plasticizers or adhesive is the chemical compatibility. Some chemical are not compatible with each other so the can react with time or one of the ingredient may induce decomposition in the other component. For a brief section on compatibility check section 5.3 of LLNL Explosives Handbook-Properties of Chemical Explosives and explosive simulants (rev.2-1985), B. Dobratz. Remember not every time you added binder you decrease sensitivity. Many published work mention that increase in sensitivity is observed with some PBX type explosive. The reason of increased sensitivity is the presence of cracks, minute bubble gas (trapped bubble gas or from explosive decomposition) induced with aging or thermal cycling. these voids can act as a potential sites for hot spot formation and thus render the explosive more easy to ignite and this by decreasing the critical pressure of initiation needed for initiation. Also, because you don't have special equipment for pressing your new explosive composition to high density, detonation performance will suffer. So be careful for these aspect with your new explosive composition.

Dany.

I didn't know the sensitising voids are such a thing. Thanks Dany.

golfpro - 28-9-2013 at 11:53

I guess the only way to tell is to test right? I have a 1gram chunk of this gum like material, I'll wait 5 days and do different hammer tests and whatnot, I really don't believe there will be any problems.

Microtek - 28-9-2013 at 14:04

It's made for glueing carpets to floors, right? And it is a solvent diluted glue, so once the solvent dries out (which it will; it is hexane and "light distillates" which means similar alkanes) you will be left with something that is more like a PBX than a plastique. Before reaching this point, you will get an inhomogenous compound as the surface dries out first.
You could try dissolving the carpet cement in a suitable solvent (more hexane or detergent gasoline) and adding some suitable plasticizer such as a relatively long chain ester, or maybe just motor oil. At any rate something that won't evaporate as readily (at least if you wan't to be able to store your new plastique).