DubaiAmateurRocketry
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Tetrazole "clicking" of GAP Curing ?
In this study (also a Ph.D. thesis):
The author showed cyano and azido clicking to form tetrazole on GAP.
Direct download link:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&...
Does that mean PBAN (polybutadiene — acrylic acid — acrylonitrile terpolymer) can cure with GAP directly through this reaction?
R—C≡N + R—N=N+=N- >>> R-Tetrazole-R
[Edited on 1-6-2017 by DubaiAmateurRocketry]
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DubaiAmateurRocketry
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bump, im really looking for an answer, whether if the tetrazole clicking of azido and cyano groups happens only in solvents or if it can happen,
assuming GAP and PBAN is miscible.
[Edited on 2-6-2017 by DubaiAmateurRocketry]
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PHILOU Zrealone
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The ionic or organic azide-cyanide clicking is a long known reaction to yield tetrazole rings...
The last times there are countles examples into the litterature to acheive it in microwave, in special solvents or in greener chemistry alternatives.
Just type into a search engine the following words "tetrazole synthesis condensation cyanide nitrile azide azido cyano" and you will get hundred of
like thesis as the one you provided us or scientific publications and papers into pdf format.
I must have like 1000 onto my PC because I have gathered info onto tetrazoles for years (> 2 decades).
Just like any other reaction the set of parameters is important...one of the main being the concentration and catalyst or solvent to overpass the
activation energy barrier to allow for the aromatic condensation (tetrazole is an aromatic pentaring) to take place.
I doubt you will be able to cure the final mix from HE/Azide containing molecule /Cyanide containing molecule...but you may stil try it.
Would be nice to have a monomolecular compound that could polymerize that way...
say N3-CH2-CN; N3-CH2-CH2-CN or N3-CH2-HE-(-CH2)-CN (HE being a High explosive core molecule)
then you would get
(-CH2-CN4-)n; (-CH2-CH2-CN4-)n or (-CH2-HE-(-CH2)-CN4-)n
Denser, less impact/heat sensitive than the related pseudo monomers CH3-CN4H ; CH3-CH2-CN4H or CH3-HE-(CH2)-CN4H...
[Edited on 2-6-2017 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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DubaiAmateurRocketry
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interesting, if PBAN and GAP are able to cure, it might result in decent mechanical properties than GAP with isocyanates.
Also, what kind of structures we'd be looking for, for plasticizers that could potentially help these two become miscible (if they are not)
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PHILOU Zrealone
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PBAN is quite a complex molecule...the annoying part is the carboxylic part making it more water soluble/hydrophile...from the acrylic acid counter
part.
GAP should be soluble into organic solvents.
If both were only organic azide or cyanide/nitrile both would be nearly 100% soluble into each other because -N3 and -CN are pseudo halides
groups...thus it would be like mixing ethyl chloride with ethyl bromide or ethyl iodide...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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DubaiAmateurRocketry
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Quote: Originally posted by PHILOU Zrealone  | PBAN is quite a complex molecule...the annoying part is the carboxylic part making it more water soluble/hydrophile...from the acrylic acid counter
part.
GAP should be soluble into organic solvents.
If both were only organic azide or cyanide/nitrile both would be nearly 100% soluble into each other because -N3 and -CN are pseudo halides
groups...thus it would be like mixing ethyl chloride with ethyl bromide or ethyl iodide... |
umm thats what i thought too.
Does that mean PBAN might be slightly soluble in GAP, but might not be miscible?
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PHILOU Zrealone
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| Quote: Originally posted by DubaiAmateurRocketry | | Quote: Originally posted by PHILOU Zrealone | PBAN is quite a complex molecule...the annoying part is the carboxylic part making it more water soluble/hydrophile...from the acrylic acid counter
part.
GAP should be soluble into organic solvents.
If both were only organic azide or cyanide/nitrile both would be nearly 100% soluble into each other because -N3 and -CN are pseudo halides
groups...thus it would be like mixing ethyl chloride with ethyl bromide or ethyl iodide... |
umm thats what i thought too.
Does that mean PBAN might be slightly soluble in GAP, but might not be miscible? |
Depends on many factors like molecular shape, lenght of hydrophobic molecular parts (into this case alkylic parts), numbers of hydrophilic groups per
unite of lengt, lenght of the molecule...
So both molecules may present partial intermutual solubilities but to what extend is hard to tell without actually experiment.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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PHILOU Zrealone
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Not stickly related but worth a try for curing...
You of course know diamino-tetrazole (DAT)...
DAT contains two NH2 groups...in theory if you allow it to react with a reactive aldehyde like formaldehyde or ethandial (glyoxal) you should get
interesting polymers...a bit like urea-formol thermo hardening resin.
Except if the two NH2 ensure for ring closure... then you would get N4C(NH)2CH2
H2N-CN4-NH2 + CH=O --> (-NH-CN4-NH-CH2-)n
H2N-CN4-NH2 + 2 CH=O --> (=N-CN4-N(-CH2-)2)n
One may even imagine the condensation reaction between tetrazolal and diamino-tetrazole...
H2N-CN4-NH2 + O=CH-CN4H --> (-NH-CN4-NH-CH(CN4H)-)n
H2N-CN4-NH2 + O=CH-CN4H --> HN4C-CH=N-CN4-N=CH-CN4H
or 1,4-tetrazine-dial and diamino-tetrazole
H2N-CN4-NH2 + O=CH-C(N4)C-CH=O --> (-NH-CN4-NH-CHOH-C(N4)C-CHOH-)n
(-NH-CN4-NH-CHOH-C(N4)C-CHOH-)n <==> (=N-CN4-N=CH-C(N4)C-CH=)n + 2 H2O
or other energetic reactive aldehydes (beware reactive often means toxic)
Trinitrobenzaldehyde O=CH-C6H2(NO2)3
Nitromalonaldehyde O=CH-CHNO2-CH=O
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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DubaiAmateurRocketry
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Do you have any sources for that?
Also, wouldnt poly-tetrazole polymers be almost a complete solid? Assuming from its structure.
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PHILOU Zrealone
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No sources...but based on a good general knowledge of organic chemistry and related like reactions
--> "in theory if you allow it to react "
--> "One may even imagine"
I thought my phrasing was clear  enough about the speculative aspect.
Hard to predict solidity at ambiant T° but I'm quite confident that a high polymer is nearly 99,9% a solid...
Now the question you had in mind was probably:
--> Does it display a low MP and/or a high glass transition temperature?
A low MP would be desirable to allow for an easy mixing and incorporation of the solid energetic mix into the polymeric matrix (curing
agent/plasticizer); a high glass transition would be desirable to allow for an easier mixing/kneeding/deformation plasticity/elasticity...
Too hard and brittle polymer would increase the risk of fissuring/breakage and into the case of a propellant this often means a CATO (explosion of the
shuttle propellant reservoir).
The polymer must thus hold very little/few crystalline domains and the resulting polymer is thus softer.
For detonic applications...a hard polymer is absolutely no problem since the aim it to allow for a superfast explosion.
A hard polymer/thus holding a lot of crystaline domains would also be beneficial to density (only a rare numbers of exceptions)...since the
arrangement of the molecular patern display a better packing and order so molecular interractions are also stronger thus favourizing molecular
attraction and denser patern.
The effect of the density/breakability onto the sensitivity is hard to predict since it depends of the weakest critical triggering link...and this can
be heat sensitivity, friction sensitivity, static sensitivity, tribo-electric sensitivity, ...
I suspect that the polymers displaying no acidity (no acidic H's like onto NH into tetrazole ring or onto side tetrazine NH arms) will be more plastic
and less brittle, thus displaying a lower MP.
The acidic compounds will have more H bonds and as a result will be more crystalline and brittle...MP will be higher.
[Edited on 14-6-2017 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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