Sciencemadness Discussion Board - Desensitize ETN? - Powered by XMB 1.9.11 (Debug Mode)

Generally speaking, plasticization of secondary explosives will always lower the sensitivity and increase handling properties which is a bonus.

The coating of the crystals of HE with lubricating inert material causes the sensitivity reduction.

It might sound like I'm stupid, but... What if I simply use ETN instead of RDX and make C-4, but with ETN?
I don't see a reason why it wouldn't work. There is no chemical reaction between the plasticizers and the explosive itself.
Actually, I think its possible to plasticize sand or any other grain-shaped substance.

greenlight - 2-11-2017 at 08:56

You are correct, it does not have to be RDX. Semetex is a plasticized PETN formulation.
There are quite a few people on here using plasticized ETN for shaped charges and the like.
The energetic has to be in the proper form via special precipitation methods for optimum density though. If using fine powder it does not come out as dense

joseph6355 - 2-11-2017 at 09:13

You are correct, it does not have to be RDX. Semetex is a plasticized PETN formulation.
There are quite a few people on here using plasticized ETN for shaped charges and the like.
The energetic has to be in the proper form via special precipitation methods for optimum density though. If using fine powder it does not come out as dense

Slower recrystallization to form larger grains?

greenlight - 2-11-2017 at 09:54

You dont want large crystals though which would end up on the sensitive side and make working in the binder dangerous.

There are many techniques and variations. I just dissolve PETN in acetone and pour slowly into heavily stirred ice-water.
Comes out granular like fine sand ready to be further processed into PE.

joseph6355 - 2-11-2017 at 11:37

You dont want large crystals though which would end up on the sensitive side and make working in the binder dangerous.

There are many techniques and variations. I just dissolve PETN in acetone and pour slowly into heavily stirred ice-water.
Comes out granular like fine sand ready to be further processed into PE.

I usually crash my ETN in ice water, but at once.
Thanks for the tip.

I'm planning on doing some impact and sensitivity tests that are repeatable.
How do I perform those tests the "official" way, like the industry and real scientists do?

greenlight - 2-11-2017 at 21:13

You will not get perfect results with homemade equipment. There is a lot of differentiating data from professional scientific tests for the same explosives. There are too many variables to get one specific sensitivity measurement in a small ball park.

Friction testing is probably too hard to reproduce accurately at home. Impact setups would be easy to make with a 2 kg weight and a large ruler, I have even seen people make melting point apparatus on here.

You can compare your results from your own testing equipment between different energetics and it will give you good results you can compare.
Just try and limit variables (samples pure, same age samples, same ambient temp on tests, ) these all make a difference. There is much data on this subject on books dedicated to explosives.

PHILOU Zrealone - 3-11-2017 at 17:19

I was thinking. Imagine the advantages of an insensitive ETN.
Its a dense and powerful explosive, the main ingredient is very cheap, and easy to get. If you use nitric acid for the nitration, the final yield is greater than the amount of erythritol added, and its also fairly easy to synthesize.

The only problem, of course, is how sensitive it is to impact.
If only we could desensitize it somehow, ETN would make a very good secondary charge.
Of course, by adding other substances we would obtain a smaller density, thus making our charge produce a inferior effectiveness/explosive amount rate.

The question is how, or even if its possible.
I had this on my mind for some days after I remembered how dynamite is made.

ETN is less dense than XPN (xylitol pentanitrate) or than MHN (mannitol hexanitrate) what are related to the family of linear nitrate esters with one NO3 group per carbon and are as easy to make and as cheap to get.
==> H-(CH(ONO2))n-H
H-(CH(ONO2))1-H methyl nitrate
H-(CH(ONO2))2-H ethandiol dinitrate (ethylene glycol dinitrate)
H-(CH(ONO2))3-H propantriol trinitrate (glycerol trinitrate)
H-(CH(ONO2))4-H butantetrol tetranitrate (erythritol tetranitrate)
H-(CH(ONO2))5-H pentanpentol pentanitrate (xylitol pentanitrate)
H-(CH(ONO2))6-H hexanhexol hexanitrate (mannitol hexanitrate)

If the right procedure is used the reaction is nearly quantitative and thus of course the weight of final product is higher than the starting alcohol... this is the case for all nitric esters and even for nitroaromatics where you exchange an H atom for a NO2 group; de facto the molecular weight increases.

The assumption that "Adding another substance will decrease the density"... is not right...this will only be true if the substance in question is of lower density than ETN (although I think that in some rare cases it can be the contrary)...
==> If the density of the added compound is similar; the density will remain nearly the same (except in some rare cases where molecular packing is changed for a reason or another)
==> If the density of the added compound is higher; the resulting density of the mix will be in principle higher (except in some rare case where molecular packing is strongly modified (lacunar/void packing)).

A lower effectiveness will be acheived if the added material is inert towards the ETN during the detonation...
For example adding very fine graphite dust (d=2,09–2,23 g/ccm) will:
1) increase density at all % over ETN
2) reduce friction sensitivity (graphite is a solid lubricant)
3) reduce static electricity sensitivity (graphite is electric current conductor)
4) increase thermic energy output up to a certain % because ETN has a positive OB what means it is too rich at oxygen...and that oxygen can be used to burn C dust during the detonation process...thus releasing the energy from
C + 1/2 O2 --> CO + energy
CO + 1/2 O2 --> CO2 + energy
5) increase detonation energy (brisance) up to another % linked to the points 1) and 4)...enthalpy and density plays a strong role into brisance and this is not per se the perfect OB mix... but this is probably close to it.

If the added substance is an active binder of nearly equal, equal or higher density and with a negative OB...then ther will be mixes of the two that will outperform the detonic parameters of both explosive appart...
==>This case is observed with NC and NG...
NG has the same problem as ETN of displaying a positive OB...
NC has a negative OB...
NC is denser than NG
Resulting blasting gelatin mix is denser than NG and is more brisant than each explosive appart...
NC is less sensitive than NG and reduces the sensitivity of NG a little into the mix...

[Edited on 4-11-2017 by PHILOU Zrealone]

PHILOU Zrealone - 3-11-2017 at 17:42

Even in its pure form, ETN cannot be used as a main charge (lets say 5kg of ETN) because of its sensitiveness (2 nm).

"nm" means nanometer...not Newton*meters ...
Nm or N*m stands for that...
N*m = J(oule) thus an energy...in the present case a falling weight

Sensitivity may be expressed as a falling height of a given weight (500g, 1kg, 2g, 5kg)... usually expressed into centimeters...
==> 2nm would be extremely sensitive no matter you use 20g or 5kg weight for the falling height determination...

NeonPulse - 3-11-2017 at 21:36

It’s not stupid. Several of us have successfully plasticised ETN with great results. The end result is heavily dependent on the shape and densities of the ETN crystals. Slow addition -Drop wise- of water and ice to a hot saturated of ETN in methanol works very well yielding a nice dense gritty ETN which shaves very well on rolling. You need to roll it a lot. I mean a lot. The Acetone formed crystals are also well suited for plastics too. You need a plasticiser to go with the binder and for an amateur Methyl Ricinoleate is probably the easiest to make and does give good results, better than motor oils alone which give a more brittle product. There’s a wealth of information scattered throughout this site but if you are interested in making decent plastic it is well worth searching for and reading up on.

Phlegmatising the ETN with 7-8% of PIB rubber with an oil will work to de sensitise the explosive well and aid the loading making it safer to press and filling the tiny voids that are left with regular pressing.

joseph6355 - 8-11-2017 at 09:44

Quote: Originally posted by PHILOU Zrealone

Even in its pure form, ETN cannot be used as a main charge (lets say 5kg of ETN) because of its sensitiveness (2 nm).

I'm sorry. I meant Newton meters (Nm).
The source of this data is wikipedia https://en.wikipedia.org/wiki/Erythritol_tetranitrate.

[Edited on 8-11-2017 by joseph6355]

MineMan - 9-11-2017 at 18:03

Well for PETN they add 5-10% wax when putting it in detcord for handling.

The same can be done with ETN. Heat it in a hot water bath to about 120F and add 10 percent wax. When friction is applied the wax melts and lubricates. It will help with static too and the spark will have to vaporize the wax coating to hit the ETN.

1% graphite dust can help to... as the master indicated above

I have tried some exotic lubricants like molybdenum or Tungsten disulfide... a warning the sulfide actually sensitizes pyrotechnic ddt mixtures.

Bert - 9-11-2017 at 18:52

Suppose you could use Viton and make it a PBX...

Attachment: RDX Viton PBX.pdf (299kB)
This file has been downloaded 784 times

Quote:

To prepare RDX/viton mixtures of various compositions, RDX and viton were separately dissolved in acetone as per desired weight content in the final mixture. The two solutions were then mixed and temperature of the resultant solution was raised to extract acetone from the solution. This resulted in RDX/viton mixtures which were dried at 70 °C in a vacuum oven at 1 torr vacuum for 8 h for complete drying and to remove occluded solvent from the mixture.

dave321 - 10-11-2017 at 11:58

sounds like viton dissolved in acetone could be good to try,
.........may be ideal from a preparation point of view.

viton a or viton b ?

Microtek - 10-11-2017 at 14:58

I have been wanting to try viton based PBXs, but was unable to find a source for soluble viton.

Bert - 10-11-2017 at 19:01

Quote: Originally posted by dave321

sounds like viton dissolved in acetone could be good to try,
.........may be ideal from a preparation point of view.

viton a or viton b ?

Lots of references to Viton A come up with a quick google search...

But there are a LOT of Viton formulations and manufacturer/dealer designations

Mychemlife - 12-11-2017 at 15:21

Is there any other platicizers other then PB, PIB that are more OTC? I can't find any PIB based amalgamating tape if any one knows a brand carried by any of the home centers. Thanks in advance.

[Edited on 11-13-2017 by Mychemlife]

joseph6355 - 12-11-2017 at 15:30

Quote: Originally posted by Mychemlife

Is there any other platicizers other then PB, PIB that are more it's? I can't find any PIB based amalgamating tape if any one knows a brand carried by any of the home centers. Thanks in advance.

I gave up the idea of plasticizing anything.
All of the plasticizes are endocrine disruptors..
I don't want that crap near me.

Mychemlife - 12-11-2017 at 18:09

I didn't know that. Ty for the info.

Bert - 12-11-2017 at 20:34

PIB or PB would usually be a binder/tacifier. The glue that holds the powdered explosive material together. Also used in various consumer products such as some brands of poster hanging adhesives.

The PLASTICIZER component of a platic explosive might be a sebacate, adipate, terepthalate, tributyl citrate or an oleate, or several other chemicals used to control handling and moulding properties. Are you entirely certain that, say, castor oil is an endocrine disruptor?

PHILOU Zrealone - 13-11-2017 at 05:02

Some rat glue brands found in brico shops at a price ranking from 2,5- 5€ are 80% pure PIB... with 20% medium volatility flamable solvent...

joseph6355 - 13-11-2017 at 21:57

PIB or PB would usually be a binder/tacifier. The glue that holds the powdered explosive material together. Also used in various consumer products such as some brands of poster hanging adhesives.

The PLASTICIZER component of a platic explosive might be a sebacate, adipate, terepthalate, tributyl citrate or an oleate, or several other chemicals used to control handling and moulding properties. Are you entirely certain that, say, castor oil is an endocrine disruptor?

Castor oil? LOL, no!
Pthalates are though. Epoxies too (they contain Bisphenol A), and also adipates.

http://onlinelibrary.wiley.com/doi/10.1111/j.1574-695X.2007....
https://en.wikipedia.org/wiki/Epoxide#Uses
https://en.wikipedia.org/wiki/Phthalate#Endocrine_disruption

If you're going to plasticize something, use gloves, respirators and glasses.
Don't let that crap get in contact with your body in any way.

Edit: tributyl citrates too.
https://academic.oup.com/biolreprod/article-abstract/96/5/11...

[Edited on 14-11-2017 by joseph6355]

Microtek - 14-11-2017 at 07:02

Reality check: Thousands of everyday items contain plasticizers from that subset. They are being phased out now (at least in the EU), but they have been in use for decades, and millions of people have been exposed to them every day of their lives without taking exceptional amounts of damage.

The dangers of handling energetic materials in the first place, as well as dealing with the nitrogen oxides are far more serious concerns IMO.

PHILOU Zrealone - 16-11-2017 at 16:45

Quote: Originally posted by Microtek

Reality check: Thousands of everyday items contain plasticizers from that subset. They are being phased out now (at least in the EU), but they have been in use for decades, and millions of people have been exposed to them every day of their lives without taking exceptional amounts of damage.

The dangers of handling energetic materials in the first place, as well as dealing with the nitrogen oxides are far more serious concerns IMO.

The problem with Endocrinian Disruptors is that:
1) even minute amounts for short exposure time (a few days) may have severe consequences
2) the effect is not observable immediately onto the exposed subject... but wel once it tries to get childrens/offsprings... or that the offsprings try to multiply...
3) effect is not only onto fertility but also onto brain development
4) here the dosis doesn't make the poison because they mimic hormones... it has an effect or the complete reverse effect depending onto the exposure/concentration and this last may be effective at extremely low concentrations...
5) additivity of various ED as a daily cocktail is completely unpredictable... industrials are playing with the future of mankind and intellect... but also with the future of many animals living into the surrounding...
Through the products we are exposed via cosmetics, plastic tools, plastics containers/cans in contact with food/beverages, food, pesticides, biocides, nanoparticles... everyone of us is exposed to more than 30 to 100 various ED each day...some of those are persistant/remanent and bio-accumulate...

Rocinante - 25-11-2017 at 11:25

Interesting paper about the sensitivity of ETN, melt cast ETN and its perfromance comapred to PETN, mercury fulminate and RDX.

http://www.wydawnictwa.ipo.waw.pl/cejem/vol_14_No_2_Early_Vi...

8027 m/s at their maximum density (1,7), impact sensitivity comparable to PETN in both cases (crystals, melt cast) and friction sensitivity about twice as high as PETN.

What would be the precise detonation pressure? 300 kbar?

[Edited on 25-11-2017 by Rocinante]

[Edited on 25-11-2017 by Rocinante]

greenlight - 26-11-2017 at 05:35

When I calculate the detonation pressure (cj pressure) for PETN with the figures you state I get:

Pcj = (1.7)(8.03)²/4 = 27.404 GPa.

When converted to kilobar, I get 273.9.
Pretty close

The calculation is not 100% exact though and can be out by 1% or so.

Dornier 335A - 26-11-2017 at 14:07

That formula underestimates the detonation pressure for many explosives. The exact version is
P = ρ D²/(γ+1)
Where γ usually varies between 2.5 and 3.1. For ETN at 1.7 g/cc, gamma is about 2.7 which gives a detonation pressure of 305 kbar.

greenlight - 26-11-2017 at 19:29

I didn't know that I read the equation is only out by a small amount.
I accidentally put 8.03 instead of 8.3 as well for VOD.
What is y for PETN then?

Using 2.7 as y +1, you get 31.65 GPa or 316.5 kbar for PETN .
This sounds closer.

[Edited on 27-11-2017 by greenlight]

Rocinante - 27-11-2017 at 10:29

Has anyone tried someting more powerful than RDX? I assume that even RDX/ETN can reach ~ 320 kbar and most HMX/binder explosives reach to only about 350 - 360 kbar.

Their report states that RDX is 4× less friction sensitive than ETN recrystalized from EtOH, which is crazy. ETN is only 5× less friction sensitive than MF.

greenlight - 27-11-2017 at 20:21

RDX is about 350 kilobar @ density 1.80.
HMX around 390 kilobar @ density 1.89.

The next explosive I think would replace HMX would be HNIW if it was not for synthesis cost problems among other things.
Approximate CJ pressure would be about 527 kilobar @ density 2.44 and massive VOD of 9.38 km/s.

Rocinante - 28-11-2017 at 01:48

I'm thinking about real world mixtures, not crystal densities. HNIW is about 400 kbar, but it is a dead thing due to PETN-like sensitivity and no fielded, practical co-crystals. I'm thinking about amateur mixtures, like.. has anyone tried keto-RDX/some nitrofurazane//melt cast ETN?

Dornier 335A - 28-11-2017 at 06:34

Even at crystal density (2.04 g/cc), HNIW only reaches about 420 kbar compared to 393 kbar for HMX at crystal density. The effect of switching to HNIW would therefore not be very significant considering the increased amount of inert material required to keep the sensitivity down.

I think I have seen RDX/ETN melt cast on youtube but it should be said that while it performs significantly better than Composition B it doesn't perform better than pure RDX. I get 8590 m/s and 337 kbar at 1.75 g/cc for a 50/50 mixture.
RDX has a very high detonation velocity for its density, so most mixtures perform worse. The only exceptions are mixtures with strong oxidizers like hexanitroethane or bis(2-difluoramino-2,2-dinitroethyl)nitroamine and those are out of reach for most amateurs.

greenlight - 28-11-2017 at 09:29

I see I was wrong with theoretical pressure for HNIW.
I thought it would be higher than just 420 kbar because of it having such high energy and the highest density out of most of the newer HE's.

Rocinante - 28-11-2017 at 10:08

Pressed RDX with 5 % of inerts does something like 310 kbar (some sources claim as low as 280 kbar and I'm aware how hard is to determine the pressure even with exp. methods), if I'm not mistaken, so the 50:50 mixture should be slightly more powerful.

[Edited on 28-11-2017 by Rocinante]

joseph6355 - 6-5-2018 at 17:40

It has been awhile... I have learned so much since the creation of this topic. I'm revisiting it now to discuss more about ETN.
I've been using trinitrophenol as a main charge for demolishing concrete structures, but the TNP proved to be toxic and dangerous.

My detonators were made using 7.92 mm (ED) and 6.35 mm (ID) stainless steel tubing that had one end closed by welding it. It was then added an amount of 1000 mg of ETN and pressed with the help of a jig in the vice. On top of it was placed an amount of 250 mg of DDNP and slightly pressed again, and finally on top of the DDNP, 200 mg of black powder was packed loosely with a wooden stick. A 6.35 mm in diameter piece of paper with a hole in the middle was placed on top of the black powder and a fuse inserted through the paper and into the black powder. All of it was then sealed and firmly held in place by filling the steel cavity to the top with hot glue.
The detonator seemed reliable on detonating cast TNP without the need of a bigger booster charge. It wasn't that difficult as some users reported here on SM.
I'm mentioning this because I wanted to say that I'm somewhat familiar with the synthesis of ETN by the addition of erythritol in mixed acids.

ETN seems like a good EM to replace TNP, but it has a higher sensitivity, so desensitizing it is a must for safe handling.
Unfortunately I don't own a press strong enough to press high diameter charges. I have always cast my explosives, so I didn't bother to look for one.

I have some questions I was hoping that someone would help me, specially because I'm scared of casting ETN
Is it possible to achieve high densities with ETN by only phlegmatizing it with 10% petroleum jelly?
My TNP charges were cast within a PET plastic tube (50 mm dia) and I had to cut the tubes with a sharp knife to extract the solid. TNP didn't stick to the walls but it stained it yellow. How easy would it be to remove the ETN block from this tube? Does ETN contract or expand upon cooling? Can I use steel or copper tubes to cast ETN if the solid is easily removable?

Plasticizers are very hard to find where I live currently. The only one I was able to find was Dibutyl phthalate. Is plasticizing ETN possible with DBP? What binders would be required?
I'm also trying to avoid plasticizers since they are endocrine disruptors.

NeonPulse - 6-5-2018 at 22:10

Ideally you should avoid casting ETN into metal tubing for safety reasons. Especially Aluminium. Some testing conducted by users here had found that ETN can reliably detonate in contact with Al under certain circumstances under heating. Generally plastic is the way to go and ETN cast in it should remove fairly easily. It does contract a little and shrinks on cooling. I think if you were to phlegmatise it this can be done using Polyisobutene or polyisobutelene as a binder and motor oil to soften it some. If you can access methanol and castor oil you can easily make safer plasticiser from it. Methyl ricinoleate is an excellent plasticiser in combination with PIB and if used in 8-10% you can easily press a nice high density charge. It is very easy to make via transesterficaton the same way bio diesel is made.
Using it in amounts of 12% or so can give you a very nice easily mouldable plastic explosive. This takes some work but the results are well worth the effort. You can attain density of 1.6g/cm3 plus if done right. This is great for an amateur job.

joseph6355 - 6-5-2018 at 22:57

Quote: Originally posted by NeonPulse

Ideally you should avoid casting ETN into metal tubing for safety reasons. Especially Aluminium. Some testing conducted by users here had found that ETN can reliably detonate in contact with Al under certain circumstances under heating. Generally plastic is the way to go and ETN cast in it should remove fairly easily. It does contract a little and shrinks on cooling. I think if you were to phlegmatise it this can be done using Polyisobutene or polyisobutelene as a binder and motor oil to soften it some. If you can access methanol and castor oil you can easily make safer plasticiser from it. Methyl ricinoleate is an excellent plasticiser in combination with PIB and if used in 8-10% you can easily press a nice high density charge. It is very easy to make via transesterficaton the same way bio diesel is made.
Using it in amounts of 12% or so can give you a very nice easily mouldable plastic explosive. This takes some work but the results are well worth the effort. You can attain density of 1.6g/cm3 plus if done right. This is great for an amateur job.

Does ETN attack metals and sensitizes itself when in contact with them?
I don't have access to polyisobutene or polyisobutelene unfortunately. Are there any other binders that I could use with methyl ricinoleate?
And indeed, methyl ricinoleate seems like a safe alternative to DBP.

Thank you.

EDIT
Can I use silicon rubber as a binder?
What should a look for when choosing different brand and types of silicon rubbers?

[Edited on 7/5/18 by joseph6355]

Bert - 7-5-2018 at 03:45

You are thinking of using the silicone sealing compounds used in construction for sealing windows, doors and around fixtures in bathrooms to replace PIB or PB in a plastic explosive mixture?

These silicone sealers cure by reacting with water vapor, the commonly available ones release acetic acid while curing. Although they can be loaded with solids before they cure, you would end up with a permanently shaped, rubbery but solid "chunk", not a soft re mouldable putty capable of being formed to whatever shape is needed at a later time.

I have seen silicone sealers such as GE Silicone II used to make propellant grains and fireworks stars, while these sealers could be used for fabricating flexible sheet explosives intended to be cut but not otherwise reconfigured after curing, they are not suited to making something like Semtex or C4.

joseph6355 - 7-5-2018 at 12:59

You are thinking of using the silicone sealing compounds used in construction for sealing windows, doors and around fixtures in bathrooms to replace PIB or PB in a plastic explosive mixture?

These silicone sealers cure by reacting with water vapor, the commonly available ones release acetic acid while curing. Although they can be loaded with solids before they cure, you would end up with a permanently shaped, rubbery but solid "chunk", not a soft re mouldable putty capable of being formed to whatever shape is needed at a later time.

I have seen silicone sealers such as GE Silicone II used to make propellant grains and fireworks stars, while these sealers could be used for fabricating flexible sheet explosives intended to be cut but not otherwise reconfigured after curing, they are not suited to making something like Semtex or C4.

Thats disappointing.
The product I mentioned is used for making these molds for casting, and also for cooking.
https://www.youtube.com/watch?v=JyQmEG9qmfw

Is there anything besides PIB that I could use?
The silicon rubber idea came from the PBX article on wikipedia.

[Edited on 7/5/18 by joseph6355]

MineMan - 7-5-2018 at 13:47

Petroleum Jelly works well. 10percent is a good value. This will provide all the desensitization you need.

joseph6355 - 8-5-2018 at 06:15

I have found a commercial product that might provide me with PIB. Its a caulk PIB-based sealant.
The datasheet provides CAS numbers as well as the concentrations.

[SUBSTANCE][CAS NUMBER][CONCENTRATION]

Synthetic Rubber (Isobutylene-Isoprene copolymer)/ 9010-85-9 / 5 to 20
Castor Oil / 8001-79-4 / 1 to 10
Naphthenic Oil / 67254-74-4 / 10 to 20
Dolomite / 16389-88-1 / 20 to 30
Talc / 14807-96-6 / 25 to 45
Polyisobutene / 9003-29-6 / 15 to 25
Carbon Black / 1333-86-4 / 0,3 to 1,0
Titanium Dioxide / 13463-67-7 / 0,5 to 2,0
Organic and Inorganic Pigments / 147-14-8 / 0,5 to 2,0

I have also found another one that contains PIB, natural rubber, dolomite, talc, castor oil, mineral oil and petroleum jelly.

Is it possible to extract the binder with solvents?
I will look myself to see if other substances could also dissolve in the solvent, if so, the solvent could be brought to its boiling temperature and slowly evaporated.
The problem is that I don't know if the substances would react with each other and render impossible the extraction of the binder.

Has someone attempted this yet with caulk sealants/adhesives? I hope so.

[Edited on 8/5/18 by joseph6355]

Bert - 8-5-2018 at 08:13

Could you provide a product name/number?

Rubber cement thinner is generally capable of dissolving rubber.

Attachment: Solvent-and-Thinner_Bestine.pdf (75kB)
This file has been downloaded 383 times

[Edited on 5-8-2018 by Bert]

joseph6355 - 8-5-2018 at 15:59

Could you provide a product name/number?

Rubber cement thinner is generally capable of dissolving rubber.

[Edited on 5-8-2018 by Bert]

It isn't found in the US or Europe.
I'm trying to find a thinner that contains n-heptane but so far no luck.

I'll keep looking for it.
Thanks Bert.

Is xylene capable of dissolving PIB?
Honestly I don't know if this method would extract anything. I'm quite frustrated.

[Edited on 9/5/18 by joseph6355]

roXefeller - 9-5-2018 at 02:30

It might extract it if you find a suitable solvent. But will the molecular weight of the extracted PIB be what you are hoping for? Dr Liptakov did a couple videos comparing PIB from different sources and showed the European tape SCAPA to perform better, I presume it had a higher molecular weight. This stuff isn't crosslinked though, like the isobutylene isoprene rubber. PIB needs the isoprene doping to provide crosslinking sites. It has the resilient nature of uncured rubber which can be mixed, warmed, extruded, or injected for the purpose of crosslinking into a final shape.

As for silicone, if you are comparing the ETN to cast TNP, the PBX with silicone will setup firm like the TNP. Keep in mind PBX aren't in general remoldable, rather solid charges pressed to shape. Waxy EM like TNT or TNP can be pressed without such binders but other material won't be dimensionally stable wit out the added intergranular cohesion.

joseph6355 - 10-5-2018 at 07:37

It might extract it if you find a suitable solvent. But will the molecular weight of the extracted PIB be what you are hoping for? Dr Liptakov did a couple videos comparing PIB from different sources and showed the European tape SCAPA to perform better, I presume it had a higher molecular weight. This stuff isn't crosslinked though, like the isobutylene isoprene rubber. PIB needs the isoprene doping to provide crosslinking sites. It has the resilient nature of uncured rubber which can be mixed, warmed, extruded, or injected for the purpose of crosslinking into a final shape.

As for silicone, if you are comparing the ETN to cast TNP, the PBX with silicone will setup firm like the TNP. Keep in mind PBX aren't in general remoldable, rather solid charges pressed to shape. Waxy EM like TNT or TNP can be pressed without such binders but other material won't be dimensionally stable wit out the added intergranular cohesion.

I think I'll give up the idea of plasticizing anything. I can't find PIB neither any product that contains it and allows its extraction.

The only alternative to achieve high density for me is to cast it, which I'm kind of scared of doing.

Bert - 10-5-2018 at 08:51

Quote:

I'm trying to find a thinner that contains n-heptane but so far no luck.

Quote:

I can't find PIB neither any product that contains it and allows its extraction.

You live in a country without gasoline, Colman camping fuel or any glue board type sticky traps.

Sounds like a nice place, no air pollution or vermin.

[Edited on 5-10-2018 by Bert]

Fulmen - 10-5-2018 at 08:55

Nonsense, I'm sure you can find PIB somewhere. Self-vulcanizing tape should be available, I got a very nice product from it. I don't remember which solvent I used, but I'm fairly sure it was an aromatic. Xylene should work. Just don't shake or stir the tape too much, the PIB will leech out of the tape leaving a soft, black rubbery mass. Breaking it up only causes it to disperse in the thick PIB-solution, and it's not something you can filter easily. So just let it stand for a few days and decant, the PIB can be precipitated out by adding acetone.

joseph6355 - 10-5-2018 at 09:44

Quote:

I'm trying to find a thinner that contains n-heptane but so far no luck.

Quote:

I can't find PIB neither any product that contains it and allows its extraction.

You live in a country without gasoline, Colman camping fuel or any glue board type sticky traps.

Sounds like a nice place, no air pollution or vermin.

[Edited on 5-10-2018 by Bert]

I didn't say anything about the solvent, but since you mentioned it, does it have to be pure heptane or I can use the purest gasoline I can find? I also don't own a distilling apparatus.
Any rat trap will yield PIB?
I found a fly trap. The description says that it is a layer of plastic with PIB to make it sticky.
PIB should be dissolved in something. It must be mineral oil or some other type of oil, I just don't know what it is.

Quote: Originally posted by Fulmen

Nonsense, I'm sure you can find PIB somewhere. Self-vulcanizing tape should be available, I got a very nice product from it. I don't remember which solvent I used, but I'm fairly sure it was an aromatic. Xylene should work. Just don't shake or stir the tape too much, the PIB will leech out of the tape leaving a soft, black rubbery mass. Breaking it up only causes it to disperse in the thick PIB-solution, and it's not something you can filter easily. So just let it stand for a few days and decant, the PIB can be precipitated out by adding acetone.

I have found plenty of self-vulcanizing tapes, but they are all EPR based. I haven't found a single one that contains PIB.
At least the solvent issue is "solved".

Bert - 10-5-2018 at 10:16

Perhaps your best course of action is to read a lot more. Search on GOOGLE with sciencemadness.org and your topic of interest, rather than the site search engine.

Look up SDS or MSDS for an over the counter product to find out what the ingredients are.

The answers to every question you have asked are here already, take the time and make the effort to look for them. Then ask questions- in the future, please give links or describe your starting sources when asking. Because it looks like you are not trying otherwise.

joseph6355 - 10-5-2018 at 10:36

Perhaps your best course of action is to read a lot more. Search on GOOGLE with sciencemadness.org and your topic of interest, rather than the site search engine.

Look up SDS or MSDS for an over the counter product to find out what the ingredients are.

The answers to every question you have asked are here already, take the time and make the effort to look for them. Then ask questions- in the future, please give links or describe your starting sources when asking. Because it looks like you are not trying otherwise.

Thanks, Bert.
I'm afraid of openly disclosing my location. People have stopped helping me when I did that.
The fact that I'm very amateur also doesn't help. I feel like people are afraid of teaching me anything.

My material sources, as I said, are caulk and a fly trap, which I'm uncertain if I can separate PIB from. I provided the chemicals are the concentrations for the caulk. I didn't upload the datasheet because its not in english, I figured that people wouldn't understand it since its an english-speaking forum.
I'm trying to get in contact with a manufactures to see if he is willing to sell me PIB in small quantities, but so far I haven't heard of them.
I have been trying hard to stay away from TNP because its very toxic.

I'm getting kind of insecure to post here, its like I'm doing something wrong, I don't know.

greenlight - 10-5-2018 at 10:53

You can also use polybutene bird repellent as binder with motor oil or methyl ricinoleate as plasticizer and roll to incorporate. I have PE with density 1.45 from this method.

Here is the self amalgamating tape for LL's method which also work well. It is not as high density but much softer and doesn't fall apart anywhere near as easy as the PB plastic. I just put a metre of it in some white spirits and store it like that and pour and evap solvent when using. Link here:

https://m.ebay.com.au/itm/Polyisobutylene-Self-Amalgamating-...

Don't try to cast the ETN for safety reasons IMO.

Your not doing anything wrong but this has been discussed so just search something like "plastic explosive sciencemadness.com" and it will come up with existing threads or use the search engine on the actual site here.

Anyone tried this variety?

Bert - 10-5-2018 at 13:33

Intertape 5517, on Amazon less than $3.00/.75"X22' roll

roXefeller - 10-5-2018 at 14:38

Never seen it before. Seems worth a look. Anyone have personal experience with rubber cement. Dr Liptakov's videos look like a jar of cement when he's done.

joseph6355 - 10-5-2018 at 21:13

You can also use polybutene bird repellent as binder with motor oil or methyl ricinoleate as plasticizer and roll to incorporate. I have PE with density 1.45 from this method.

Here is the self amalgamating tape for LL's method which also work well. It is not as high density but much softer and doesn't fall apart anywhere near as easy as the PB plastic. I just put a metre of it in some white spirits and store it like that and pour and evap solvent when using. Link here:

https://m.ebay.com.au/itm/Polyisobutylene-Self-Amalgamating-...

Don't try to cast the ETN for safety reasons IMO.

Your not doing anything wrong but this has been discussed so just search something like "plastic explosive sciencemadness.com" and it will come up with existing threads or use the search engine on the actual site here.

Thanks!
I found a product for sealing headlamps in cars.. It is "butyl-rubber" based.
From the pictures I can see that they separate the layers to prevent the rubber from fusing with itself.

Do you guys think its worth a try?
How long should I leave it in heptane before using? Can I speed things up by applying heat?
I'm looking for a density of at least 1.6 g/cm³ so I can obtain a high VoD (+7800 m/s)

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[Edited on 11/5/18 by joseph6355]

Bert - 10-5-2018 at 21:48

Anyone have personal experience with rubber cement. Dr Liptakov's videos look like a jar of cement when he's done.

Rubber cement is natural latex from rubber trees, dissolved in a suitably fast evaporaring solvent in my experience. Certainly it COULD be used as a binder for a plastic explosive, and at times it certainly has been so used.

One should look at the parameters which caused military and industrial plastic explosives manufacturers to make the choices they did.

Personally, I use rubber cement by the gallon can on movie and video sets as an accelerant for fire effects. Heptane is reasonably low in volatility, allowing a bit of time from rigging the effect to lighting it, yet volatile and low enough flashpoint that it is responsive and reliable enough regarding ignition for our uses.

joseph6355 - 11-5-2018 at 03:33

I deeply thank you guys. I found a rat trap that is composed by 90% PIB, 5% Isobutylene elastomer and 5% unknown inert materials.

Two questions.
1. Is the Isobutylene elastomer a concern?
2. PIB is soluble in many solvents, I'd like to know what solvents it isn't soluble in.
The plan is to wash the PIB with this solvent to try and remove the 5% unknown inert chemicals, and hope that it removes it.

I basically found concentrated PIB for sale as an OTC product. Most of rat traps contain smaller concentrations of PIB.
The product is manufactured locally by a small company that is based close to where I live.
Oh, is there a significant difference in performance between using Dibutyl phthalate or mineral/vegetable oil as the plasticizer?
Can I also phlegmatize ETN and also plasticize it at the same time? Will it make a difference? I was thinking about adding 1% petroleum jelly along with the binder and plasticizer.

Edit: I found another one that is made from polybutene and an unknown "inert polymer".

[Edited on 11/5/18 by joseph6355]

Bert - 11-5-2018 at 05:12

No additional phlegmatizer is needed.

joseph6355 - 13-5-2018 at 11:12

The MSDS from the bird repellent that I found says that it is composed by 80% polybutene and 20% of inert materials. It is gummy, transparent and whitish in appearance.
If it only contains 20% by weight of oil, it should be a good plasticizing mix, right? By the looks of it, there isn't any dye or other solids in the mixture.
Should I add 25-30% of extra methylricinoleate to the mixture?

This is looking good so far.
What velocities would I be getting at 1.45ish g/cm³, 7500 m/s?

Would dissolving the binder/oil in solvent and then adding the EM and mixing it until the solvent evaporates result in a better mixture instead of just adding the EM to the gummy mass?

[Edited on 13/5/18 by joseph6355]

Rocinante - 13-5-2018 at 12:39

You need to roll that plastic on a suitable surface with some protective gear - crystal shaving inside that plastic is going to increase the density.

Also, our guys from Explosia have some success with re-crystalizing PETN from solutions that contain 1 % of stearic acid - they can make PETN crystlas that are completely comparable to RDX. It might work for ETN, too.

joseph6355 - 13-5-2018 at 13:58

You need to roll that plastic on a suitable surface with some protective gear - crystal shaving inside that plastic is going to increase the density.

Also, our guys from Explosia have some success with re-crystalizing PETN from solutions that contain 1 % of stearic acid - they can make PETN crystlas that are completely comparable to RDX. It might work for ETN, too.

"Shaving ETN" sounds dangerous. LOL.
What do you mean by "comparable to RDX"? You mean they are smaller?

Rocinante - 13-5-2018 at 15:10

Comparable in friction and impact sensitivity to RDX.
Shaving referes to the plastic itself, you take 1 g piece of your plastic and you roll it with a wooden cylinder on a smooth surface. I've never hear of an accidental detonation doing that but be sure to wear earpro, gloves and body protection (leather, kevlar...) - one pair of polycarbonae glasses isn't enough, face shield + glasses should do the trick

joseph6355 - 14-5-2018 at 01:06

Comparable in friction and impact sensitivity to RDX.
Shaving referes to the plastic itself, you take 1 g piece of your plastic and you roll it with a wooden cylinder on a smooth surface. I've never hear of an accidental detonation doing that but be sure to wear earpro, gloves and body protection (leather, kevlar...) - one pair of polycarbonae glasses isn't enough, face shield + glasses should do the trick

But the ETN crystals will scratch against each other inside the putty mass, right?
Wouldn't pressing the putty be safer than rolling?
The putty will be homogeneous anyway, because I'll dissolve the plasticizing mixture in a solvent and add the EM bit by bit while mixing.

I was also thinking about adding a dye to mimic Semtex, just for the looks.

Rocinante - 14-5-2018 at 01:12

I don't think that pressing would increase the density like rolling. Ys, the crystals are going to scratch against each other. Yes, dye is OK.

You can easily reach 1.5 and 7500 m/s+ with ~ 225 kbar. Most Semtex formulatios are near 1.45 and 180 - 220 kbar. There is a blakc one, PlNp 10 - 85 % PETN, Red and Yellow - 80 % RDX/PETN mix. Your plastic is likely to be slightly more powerful - but you're not likely to get to 1.5 without rolling.
Using 2 crystals sizes prior to plastification is a good practice, too - higher density, you may use 20 % large crystlas and 80 % of fine crystals.

joseph6355 - 14-5-2018 at 01:21

I don't think that pressing would increase the density like rolling. Ys, the crystals are going to scratch against each other. Yes, dye is OK.

You can easily reach 1.5 and 7500 m/s+ with ~ 225 kbar. Most Semtex formulatios are near 1.45 and 180 - 220 kbar. There is a blakc one, PlNp 10 - 85 % PETN, Red and Yellow - 80 % RDX/PETN mix. Your plastic is likely to be slightly more powerful - but you're not likely to get to 1.5 without rolling.
Using 2 crystals sizes prior to plastification is a good practice, too - higher density, you may use 20 % large crystlas and 80 % of fine crystals.

Man, that sucks. :\
Its like there isn't a "safe" way to achieve high densities.
I'll use 10% binder + 90% ETN recrystallized from Ethanol.

Btw, can gasoline or any other solvent attack ETN or decompose it in any way?
Is it okay to leave plasticized ETN in contact with metals like steel or copper?

[Edited on 14/5/18 by joseph6355]

Rocinante - 14-5-2018 at 01:31

Yes, recrystalized or double-recrystalized ETN plastic that is free of acid is quite safe. You can roll small bits and you can use a very thick wooden cylinder - very little risk even in case of detonation (+ body protection). Gasoline is unlikely to decompose ETN.

joseph6355 - 20-5-2018 at 17:59

Yes, recrystalized or double-recrystalized ETN plastic that is free of acid is quite safe. You can roll small bits and you can use a very thick wooden cylinder - very little risk even in case of detonation (+ body protection). Gasoline is unlikely to decompose ETN.

Sorry I didn't report back, I was waiting for the bird repellent to arrive.
As you can see, it is 90% polyisobutylene, 5% isobutylene elastomer (aka rubber) and 5% inert materials.
The consistence of the repellent is of a very thick and viscous paste. It is opaque and milky in color.

I prepared 1.1g of the repellent and 1g of mineral oil + 20g of dough. I dissolved everything in gasoline and it is drying now.
At first I thought that the mineral oil wasn't thick enough to make it like a putty, but now it is starting to look and feel like a plasticized solid.
I can't wait to see how it is going to turn out when I make ethanol free gasoline and use a proper plasticizer.

The repellent weighs 265 g of net product per canister and it costs about 4.55 usd.
Do you guys think that it is a better alternative to the SCAPA tape? If there is any oil in it, it is limited to the 5% inert materials, and it is very cheap for the amount of PIB that it contains.

roXefeller - 22-5-2018 at 17:35

To follow up on this statement with some references, I'm attaching two patents. The first is the old patent for RDX PBX compositions. It states that the preferential PIB polymer molecular weight is between 100,000 and 140,000. The second patent in the background of prior art details the physical properties of various PIB polymer molecular weights. The cold flowing and tacky polymer is in the range of 40,000 and 100,000. The low tack rubbery polymer without cold flow is in the higher range. This is the sample that Dr Liptakov has identified. I suspect the formulators chose this because it had some tack for adhesion, but lacked the cold flow which is essentially fluid strain velocity at moderate shear stress. While rubber that doesn't cold flow will exhibit a solid strain field without velocity under shear stress.

This isn't to say that other polymers couldn't replace PIB. I've seen numerous reports from Lawrence Livermore that propose new compositions.

Bert, the tape that you asked about above, I tested some of it. It swells in the heptane much like the silicone based tape. It doesn't dissolve like the SCAPA tape.

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joseph6355 - 23-5-2018 at 21:15

Is it possible to measure the molecular weight of the PIB that I have available?

[Edited on 24/5/18 by joseph6355]
Sorry, I hadn't seen the attached files.

"Polyisobutylene with a molecular weight of from about
1,000 to 5,000 is an oil. The polyisobutylene with a molecular weight of from about 5,000 to 18,000 is of a consistency similar to chewing gum and the polyisobutylene of molecular weight of about 18,000 to 40,000 is a semi-solid, tacky, plastic mass. The polyisobutylene with a molecular weight of from about 40,000 to 100,000 is a tacky elastic solid that has cold flow properties. The polyisobutylene of about 100,000 to 300,000 molecular weight is a rubber-like, strong elastic polymer of low tacki
ness, with no cold flow properties at room temperature."
It appears that my PIB ranges from 18000 to 100000. Maybe I could upload a video and ask for opinions on it.

[Edited on 24/5/18 by joseph6355]

joseph6355 - 20-6-2018 at 05:52

Ok, it appears that I have found a good source of PIB.
Here is a video of 8.7 % PIB and 91.3 % flour.
https://vimeo.com/276031986
The password is the name of this forum without spaces or capital letters.

The product is a tire repair patch.
https://i.imgur.com/EKNnYLq.jpg
https://i.imgur.com/zIM5JTk.jpg

The extracted PIB is a very dark brownish red, it doesn't stick as rat trap glue does, but it still does to a certain degree. The PIB alone smells like rubber, and you can stretch it like bubble gum to a certain point, then it breaks. It is not malleable, it is more like a chunk of rubber that needs strong pressure to conform or stretch.
The data sheet says it contains PIB, butyl rubber, oil and fibers.

I dissolved 60 patches in about a liter of Hexane. The PIB dissolves, but the fibers stay as a solid, which can be easily picked out by hand and squeezed.

One problem that I have encountered is that the putty isn't a solid like modeling clay. It feels kind of porous after you break it in half or play with it.
https://i.imgur.com/GjRrNsE.jpg
But you can make it more solid by compacting it with your hands. Maybe thats because the flour is rather powderish, more than fine sand.
It does not fall apart by itself and feels very solid after compacted.
https://i.imgur.com/DZQrc9g.jpg
https://i.imgur.com/v5Fpw1E.jpg

Would adding methylricinoleate help to improve it somehow?
The amount of PIB added is rather low. Increasing it to 15 % would help to make it more solid, I believe. And using actual crystals instead of very fine grains would require less inerts.
Regarding methylricinoleate, can I use Ethanol instead of Methanol?

[Edited on 20/6/18 by joseph6355]

[Edited on 20/6/18 by joseph6355]

roXefeller - 20-6-2018 at 07:02

That sounds promising for the PIB you extracted. For the USA, I'll continue to source mine from tape I found on eBay.

Quote:

Regarding methylricinoleate, can I use Ethanol instead of Methanol?

Do you mean will ethylricinoleate work as a plasticizer? I don't know.
Or, Will ethanol produce methylricinoleate? No, it is a different functional you are estering with.

joseph6355 - 20-6-2018 at 07:40

That sounds promising for the PIB you extracted. For the USA, I'll continue to source mine from tape I found on eBay.

Quote:

Regarding methylricinoleate, can I use Ethanol instead of Methanol?

Do you mean will ethylricinoleate work as a plasticizer? I don't know.
Or, Will ethanol produce methylricinoleate? No, it is a different functional you are estering with.

How didn't I think about it? LOL.
I'll make sure to use Methanol instead. Thanks.

markx - 24-6-2018 at 23:08

That sounds promising for the PIB you extracted. For the USA, I'll continue to source mine from tape I found on eBay.

Quote:

Regarding methylricinoleate, can I use Ethanol instead of Methanol?

Do you mean will ethylricinoleate work as a plasticizer? I don't know.
Or, Will ethanol produce methylricinoleate? No, it is a different functional you are estering with.

How didn't I think about it? LOL.
I'll make sure to use Methanol instead. Thanks.

Actually regular motor oil also works very good as a plasticizer in combination with the high molecular weight PIB from tape. Just in case you are not inclined to synthesize the ricinoleate esters, but it is an educational excercise on it's own to go through with it.
Use a 50/50 mix by weight of PIB/oil as a solution of known concentration and add in about 10% content to the material that you want to bind.

joseph6355 - 25-6-2018 at 09:28

Quote: Originally posted by markx

That sounds promising for the PIB you extracted. For the USA, I'll continue to source mine from tape I found on eBay.

Quote:

Regarding methylricinoleate, can I use Ethanol instead of Methanol?

Do you mean will ethylricinoleate work as a plasticizer? I don't know.
Or, Will ethanol produce methylricinoleate? No, it is a different functional you are estering with.

How didn't I think about it? LOL.
I'll make sure to use Methanol instead. Thanks.

What motor oil should I use? The thickest one that I can find?
Will the plasticizer help with the brittleness and porousness that is present in the mass?
And is there a significant difference between the motor oil and the ricinoleate? I already bought the castor oil just for this purpose, but I don't feel like buying the methanol too if the result will be the same no matter which one I choose as a plasticizer.
Just out of curiosity, castor oil alone wouldn't be useful as plasticizer, right?

roXefeller - 27-6-2018 at 17:56

Not to sound too much like aga but this sounds like a chance for you to perform a rather simple experiment and learn the effects with your own hands for the many options.

DrManhattan - 29-6-2018 at 19:55

I have found Nitrocellulose to be a great way to desensitize ETN. Mix the NC in acetone to produce a homogeneous mixture then add the ETN. Stir and mix the solution and then pour into a cast and let the acetone evaporate. Since acetone dissolves both of the materials it is a very easy way to get a uniform mixture of energetic and binder. I use a 85/15 ratio of ETN/NC.

joseph6355 - 29-6-2018 at 23:05