Origin of the paint that was found as red-gray chips - any ideas?

[newton3376]

Actually, we already know fairly well.
Analysis of the organic matrix is missing, and of course more work on the gray layer. Some better XEDS data, especially beyond 10keV, and with better resolution, would be helpful, but what we have is 90% of what we need.
Of course, XRD would show clearly and beyond any residual doubt that we are correct about hematite and kaolinite, but we are already sufficiently certain about that: The relative amounts of Si and Al are too good a fit for Al₂Si₂O₅(OH)₄, and the platelike crystal structure look so very much like kaolinite, that there really is no doubt here. We can also be very sure that there is no Si and Al in the mix outside of kaolinite, so there is no free (elemental) Al in these chips at all. We know that aluminiumsilicate, of which kaolinite is one form, are part of many paints, including one particular primer used on a great deal of WTC steel - it all falls into place.

I need to read again the several threads on this topic....that will take me several days.....

I'm just baffled that no truther insists that they submit the dust for independent testing.....

 

[bill smith]

http://forums.randi.org/showpost.php?p=7484691&postcount=677

delete double post

 

[bill smith]

I need to read again the several threads on this topic....that will take me several days.....

I'm just baffled that no truther insists that they submit the dust for independent testing.....

This may help explain..

http://www.internationalskeptics.com/forums/showpost.php?p=7484691&postcount=677 hyperlink

 

[Ivan Kminek]

Finally some (partial) info on the thermal degradation of epoxide resins (both under air and under inert gas)

Let me repeat (mostly for the accidental visitors):
Harrit et al. observed exothermic peaks on DSC curves of red-gray chips about 420 ^oC
Laclede primer paint contained epoxide binder cured/crosslinked/hardened by some polyamine. Our question therefore is: could this binder show the similar exotherms at these temperatures (between ca 380 and 450 ^oC?)

In the research of thermal behavior of polymers (like epoxides), two methods are widely used:
1) TGA (thermogravimetric analysis). Here, the sample (1-2 mg is enough) is slowly heated and the loss of material is observed as a function of temperature. The thermal degradation of polymers is always accompanied with such a loss, since polymer chains (or three-dimensional polymeric networks like in the case of epoxides) are gradually degraded/cleaved and low molar mass compound are formed which evaporate at such high temperatures. TGA is generally used for the measurements of polymer degradation.
2) DSC (differential scanning calorimetry). The sample is again slowly heated (few mg is enough) and the heat evolved/consumed by various procceses are again recorded with an increasing temperature. This method is excellent for the investigation of e.g. phase transitions in polymers (crystallization, melting), in which the overal amount of material remains constant, but... it is not very suitable for the degradation of polymers where the loss of material is substantial. Therefore, DSC measurements of the thermal degradation of polymers are not very common.

After some hour spent with our experts on DSC and TGA and after some literature search I can write here now:

The rapid thermal degradation of polymers as recorded by TGA (both purely thermal and oxidative) proceeds very frequently just in the range between 400 and 450 ^oC. The usual onset is slightly below 400 ^oC. You can find some typical examples here: http://depts.washington.edu/mseuser/Equipment/RefNotes/TGA_Notes.pdf and there is also a TGA curve of some epoxide in Fig. 3 Even (quite complicated heteroaromatic) polymers synthesized by me show the same rapid degradation in this region, both under air and under argon, see corresponding figures in my/our recent papers: http://onlinelibrary.wiley.com/doi/10.1002/pola.24022/abstract http://onlinelibrary.wiley.com/doi/10.1002/pola.24780/abstract.

The same is valid also for epoxides. To my slight surprise, these highly crosslinked networks also rapidly degrade within the same "suspicious" temperature range even under inert atmosphere with a very substantial loss of mass, see e.g. these papers:
Polymer Degradation and Stability Volume 80, Issue 2, 2003, 383-391
Journal of Materials Science Volume 36, Number 18, 4405-4409
Polymer Degradation and Stability Volume 56, Issue 3, June 1997, Pages 291-299
Polymer Letters Vol.3, No.8 (2009) 501–509 etc.

Dr. L. Matejka from our institute explained me: the high temperature causes a cleavage of epoxide resin to shorter segments and volatile compounds like aromatic and aliphatic stuffs. If the air /oxygen is present, these segment/compounds are quickly oxidized and more heat is evolved. Roughly: the presence of oxygen usually lead to the degradation at slightly lower temperatures and with increased rate. This is, in fact, the manner how epoxides (and many other polymers) burn at temperatures between 400 and 500 ^oC.

So I still think that epoxide resins can thermally behave like red-gray chips. But, the degradation chemistry of epoxide resins is quite complicated and depends on many factors, including used hardener, the overal structure, the content of fillers (e.g. inorganics like Fe₂O₃ of aluminosilicates etc. Direct DSC measurements of more red-gray chips (best in the correlation with TGA) is still needed…

 

[Sunstealer]

Where on the attached chart do you think the grey material would fit ? From 0.001 to 100 ?
http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/strength-toughness/IEChart.html

Towards the ceramics.

Finally some (partial) info on the thermal degradation of epoxide resins (both under air and under inert gas)

Let me repeat (mostly for the accidental visitors):
Harrit et al. observed exothermic peaks on DSC curves of red-gray chips about 420 ^oC
Laclede primer paint contained epoxide binder cured/crosslinked/hardened by some polyamine. Our question therefore is: could this binder show the similar exotherms at these temperatures (between ca 380 and 450 ^oC?)


After some hour spent with our experts on DSC and TGA and after some literature search I can write here now:

The rapid thermal degradation of polymers as recorded by TGA (both purely thermal and oxidative) proceeds very frequently just in the range between 400 and 450 ^oC. The usual onset is slightly below 400 ^oC. You can find some typical examples here: http://depts.washington.edu/mseuser/Equipment/RefNotes/TGA_Notes.pdf and there is also a TGA curve of some epoxide in Fig. 3 Even (quite complicated heteroaromatic) polymers synthesized by me show the same rapid degradation in this region, both under air and under argon, see corresponding figures in my/our recent papers: http://onlinelibrary.wiley.com/doi/10.1002/pola.24022/abstract http://onlinelibrary.wiley.com/doi/10.1002/pola.24780/abstract.

The same is valid also for epoxides. To my slight surprise, these highly crosslinked networks also rapidly degrade within the same "suspicious" temperature range even under inert atmosphere with a very substantial loss of mass,

Dr. L. Matejka from our institute explained me: the high temperature causes a cleavage of epoxide resin to shorter segments and volatile compounds like aromatic and aliphatic stuffs. If the air /oxygen is present, these segment/compounds are quickly oxidized and more heat is evolved. Roughly: the presence of oxygen usually lead to the degradation at slightly lower temperatures and with increased rate. This is, in fact, the manner how epoxides (and many other polymers) burn at temperatures between 400 and 500 ^oC.

Thanks Ivan - polymer chemistry isn't my strong point. It's interesting to have confirmation from experts that these materials will degrade in the exact region we are interested in. I suspected so. Look at these TGA thermograms

http://www.springerimages.com/Images/Chemistry/1-10.1007_s00289-009-0052-0-6
http://www.springerimages.com/Images/Chemistry/1-10.1007_s00289-009-0052-0-7
http://www.springerimages.com/Images/MaterialScience/1-10.1007_s10854-009-9991-3-4

I also wondered why it was so difficult to find DSC thermograms, thanks for the answer on that one.

I think there is plenty of evidence to suggest that this material is Laclede standard paint rather than thermite.

I'd be interested to see what your experts make of this truther video http://www.youtube.com/watch?v=t-pFbJzTG_E&feature=player_embedded

It's certainly not thermite.

Cheers.

 

[alienentity]

. I have a hunch that there was much more LaClede primer in the towers than Tnemec.

Good hunch. My in-head calculation is yes, unless I'm thinking of the floor system structure in the wrong way. (I'm assuming the steel floor deck would have been painted with LaClede).

ETA nevermind, I see you guys already covered that and decided the decks were probably galvanized...

Another thing we should do is to ignore Bill Smith, unless he provides constructive critique and helpfull hints, rather than displaying his ignorance and trollishness.

I've had BS on ignore for a long time. I don't care whether he's a troll or not....makes no difference to me.

 

[bill smith]

Towards the ceramics.


Thanks Ivan - polymer chemistry isn't my strong point. It's interesting to have confirmation from experts that these materials will degrade in the exact region we are interested in. I suspected so. Look at these TGA thermograms

http://www.springerimages.com/Images/Chemistry/1-10.1007_s00289-009-0052-0-6
http://www.springerimages.com/Images/Chemistry/1-10.1007_s00289-009-0052-0-7
http://www.springerimages.com/Images/MaterialScience/1-10.1007_s10854-009-9991-3-4

I also wondered why it was so difficult to find DSC thermograms, thanks for the answer on that one.

I think there is plenty of evidence to suggest that this material is Laclede standard paint rather than thermite.

I'd be interested to see what your experts make of this truther video http://www.youtube.com/watch?v=t-pFbJzTG_E&feature=player_embedded

It's certainly not thermite.

Cheers.

Thanks for that. To me it looks like something inside the chip reacts causing the swelling and giving off gas. That's not metal I see inside is it ?

PS it also looks like the reactive substance inside the chip reacts and gives off gas before the main ignition,

 

[bill smith]

Sunstealer are all the ingredients in the grey layer also present in the red layer ?

 

[Sunstealer]

Ivan, thanks for the interesting details on electrophoretic deposition!


Surely.
Phosphorus is next to Al (13), Si (14) and S (16) in atomic number, which are all clearly detectable by XEDS. It has the following edge energies:
K-alpha: 2.015 keV
K-beta: 2.136keV
K: 2.149
Fig. 6 of Harrit e.al. shows no discernable peaks above noise around 2.1keV.

Phosphating is a chemical process which converts a metallic surface to a non-metallic surface by chemically bonding a phosphate coating to the metal. The phosphate coating therefore forms an integral part of the surface composition.

I've no idea whether this P would show up in the gray layers. P is observed in a couple of the spectra in the paper. Fig 18 is labelled as such too.

You should specifically ask if the process would oxidize a surface layer of the steel.

Depends if the steel structure is the anode or the cathode.

When I was at school there was a little phrase or saying to help you remember whether the anode or cathode was oxidised or reduced. Shame I've forgotten it!

The anode is oxidising and the cathode is reducing.

If the steel is the anode then you will get oxidisation and partial dissolution of the steel. Same as when you have a cell for electroplating. Remember metals form an oxide layer on contact with air so there will be a layer of oxidised material anyway.

 

[alienentity]

LOL, I've had a guy on my channel telling me I don't understand DSC, or the thermite reaction. He's partially right, but then I'm not offering my personal opinion, but merely representing the criticisms made by those who DO understand these things.

If you guys would like to engage this fella (he's apparently married to a scientist, so he's not a typical truther - they're usually scientists dabbling outside their fields of expertise... ) go to:

http://www.youtube.com/all_comments?v=EY3nj728WPY

I think he's afraid to venture onto JREF discussions. As he should be..

 

[bill smith]

Towards the ceramics.



Cheers.

Ceramic,noun.. def..[ an artifact made of hard brittle material produced from from nonmetallic minerals by firing at high temperatures]

 

[Mr. Skinny]

Ceramic,noun.. def..[ an artifact made of hard brittle material produced from from nonmetallic minerals by firing at high temperatures]

towards [təˈwɔːdz tɔːdz]
prep 1. in the direction or vicinity of towards London
2. with regard to her feelings towards me
3. as a contribution or help to money towards a new car
4. just before towards one o'clock
5. Irish in comparison with it's no work towards having to do it by hand Also toward

 

[Oystein]

Good hunch. My in-head calculation is yes, unless I'm thinking of the floor system structure in the wrong way. (I'm assuming the steel floor deck would have been painted with LaClede).

ETA nevermind, I see you guys already covered that and decided the decks were probably galvanized...

Yes, but the floor trusses... I haven't had the time to look through construction details... how many trusses are there per floor?
I also need to learn the correct terminology. Each truss (joist?) consists of a top and a bottom "beam", connected by smaller diagonal pieces.

Looking at Figure 4-7 in NCSTAR 1-6 right now:
Floors were about 3.75m high on average; with 240 perimeter and 47 core columns, that's 416 meters of column per floor. However, a typical office floor had 1400 meters of primary trusses and 600 meters of bridging trusses. Columns are wider, but I guess that does not offset the fact that trusses were 5 times longer on aggregate than columns.

 

[Oystein]

Phosphating is a chemical process which converts a metallic surface to a non-metallic surface by chemically bonding a phosphate coating to the metal. The phosphate coating therefore forms an integral part of the surface composition.

I've no idea whether this P would show up in the gray layers. P is observed in a couple of the spectra in the paper. Fig 18 is labelled as such too.

Yep

Depends if the steel structure is the anode or the cathode.

When I was at school there was a little phrase or saying to help you remember whether the anode or cathode was oxidised or reduced. Shame I've forgotten it!

The anode is oxidising and the cathode is reducing.

If the steel is the anode then you will get oxidisation and partial dissolution of the steel. Same as when you have a cell for electroplating. Remember metals form an oxide layer on contact with air so there will be a layer of oxidised material anyway.

Ivan wrote:

...
More specifically, an epoxide paint (like Laclede primer under discussion) forms colloid particles, consisting mostly of pigment and adducts of epoxide oligomers with amine hardener. Such an hardener is basic (positively charged) so the colloid particles migrate to the cathode (painted steel) in this case.
...

Too tired now to check this for plausibility. But if you two are right, then the electropainting should not add to oxidation of steel.

 

[leftysergeant]

Just the usual milling process produces a thin layer of oxided iron on steel bar stock. I have not seen any good photos of the assembled trusses before painting, but I would assume they were made by a rolling process, thus would be covered in the usual grey to black oxide layer. I have seen the angled parts begin fabricated, and they appear a bit lighter, thus may have been formed by a different process. This element was, of course a smaller percentage of the total surface area of the truss assemblies.

It was my impression that not all the chips were red/grey. I would expect there to be some relation between the number of red/grey and all red chips to the comparative surface areas of the two elements of the trusses, with the all red chips coming mostly from the angled ties.

(We need to establish the nomenclature of the parts of the truss assembly if we look any closer at this element.)

 

[Ivan Kminek]

Thanks for that. To me it looks like something inside the chip reacts causing the swelling and giving off gas. That's not metal I see inside is it ?

PS it also looks like the reactive substance inside the chip reacts and gives off gas before the main ignition,

I think (but cannot be sure) that this video show what might be expected for, e.g., a paint particle containing epoxide (see above): epoxide was first degraded by the flame and volatile degradation products (a fume visible) were then ignited by the still hot particle.
Remember: volatile compounds are what in fact burn even when you ignite a wood in your fireplace - this is the reason why it is not so easy to ignite it. On the other hand, a burning of this particular particle looks to be too slow for any thermite. (What about to buy some epoxy red primer, cure it and record some (micro)video of its burning? I am going to visit some hobby shop...) Concerning metallic or shiny appearence - photos and videos from the microworld are rather treacherous for our eyes - many things look shiny when magnified.

Sunstealer are all the ingredients in the grey layer also present in the red layer ?

A strange question, after all this discussion. According to XEDS, gray layers contain just iron, oxygen a some carbon - and these elements were also present in the red layers of all chips.

Yep Too tired now to check this for plausibility. But if you two are right, then the electropainting should not add to oxidation of steel.

After some more search I am quite sure that common epoxides hardened by amines are deposited on the cathode in the electrocoating process.

Looking at Figure 4-7 in NCSTAR 1-6 right now:
Floors were about 3.75m high on average; with 240 perimeter and 47 core columns, that's 416 meters of column per floor. However, a typical office floor had 1400 meters of primary trusses and 600 meters of bridging trusses. Columns are wider, but I guess that does not offset the fact that trusses were 5 times longer on aggregate than columns.

Some (much) more thorough calculations are welcome Btw, we expect so far that the Laclede primer was stripped out from the steel joists during collapses to the quite high extent, since it can explain the abundance of paint particles in the dust. Looking again to some photos of the floor joist steel (post #206, link http://www.drjudywood.com/articles/JJ/JJ5.html Fig. 14) this steel looks more rusty than painted. But, this rusty color can be to some extent also a result of mixing of colours of iron oxide (red) and strontium chromate (yellow) in the paint. I would like to possess a piece of this widely twisted steel...

 

[bill smith]

Just the usual milling process produces a thin layer of oxided iron on steel bar stock. I have not seen any good photos of the assembled trusses before painting, but I would assume they were made by a rolling process, thus would be covered in the usual grey to black oxide layer. I have seen the angled parts begin fabricated, and they appear a bit lighter, thus may have been formed by a different process. This element was, of course a smaller percentage of the total surface area of the truss assemblies.

It was my impression that not all the chips were red/grey. I would expect there to be some relation between the number of red/grey and all red chips to the comparative surface areas of the two elements of the trusses, with the all red chips coming mostly from the angled ties.

(We need to establish the nomenclature of the parts of the truss assembly if we look any closer at this element.)

There might be some useful pictures here Sarge.
http://www.youtube.com/watch?v=A5MRzWLdpzg&feature=player_embedded

 

[Oystein]

There might be some useful pictures here Sarge.
http://www.youtube.com/watch?v=A5MRzWLdpzg&feature=player_embedded

Thanks!
Source is here:
http://911datasets.org/index.php/NIST_FOIA_09-42_-_ic911studies.org_-_Release_29
(That page links to Bittorrent download)

 

[bill smith]

I think (but cannot be sure) that this video show what might be expected for, e.g., a paint particle containing epoxide (see above): epoxide was first degraded by the flame and volatile degradation products (a fume visible) were then ignited by the still hot particle.
Remember: volatile compounds are what in fact burn even when you ignite a wood in your fireplace - this is the reason why it is not so easy to ignite it. On the other hand, a burning of this particular particle looks to be too slow for any thermite. (What about to buy some epoxy red primer, cure it and record some (micro)video of its burning? I am going to visit some hobby shop...) Concerning metallic or shiny appearence - photos and videos from the microworld are rather treacherous for our eyes - many things look shiny when magnified.



A strange question, after all this discussion. According to XEDS, gray layers contain just iron, oxygen a some carbon - and these elements were also present in the red layers of all chips.



After some more search I am quite sure that common epoxides hardened by amines are deposited on the cathode in the electrocoating process.



Some (much) more thorough calculations are welcome Btw, we expect so far that the Laclede primer was stripped out from the steel joists during collapses to the quite high extent, since it can explain the abundance of paint particles in the dust. Looking again to some photos of the floor joist steel (post #206, link http://www.drjudywood.com/articles/JJ/JJ5.html Fig. 14) this steel looks more rusty than painted. But, this rusty color can be to some extent also a result of mixing of colours of iron oxide (red) and strontium chromate (yellow) in the paint. I would like to possess a piece of this widely twisted steel...

Thanks Ivan. Would you say that the amount of oxygen present in the grey layer is surprisingly high ?

 

[beachnut]

Thanks Ivan. Would you say that the amount of oxygen present in the grey layer is surprisingly high ?

No. That layer has less O than rust, rust is part of thermite, and the red layer is not thermite. Where is the thermite?

Would you say there is a lot of carbon in thermite? Got any ideas? Got chemistry?