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hodges
National Hazard
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Interesting. I'm purifying some aspirin now and once dry will try adding formalin to it both in pure form (acetylsalicylic acid) and after removing
the acetyl group (salicylic acid) to see if either of them produces a plastic.
Hodges
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chemoleo
Biochemicus Energeticus
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Tacho, just to point out, casein actually reacts with formaldehyde jsut like any other protein. There are free amides on proteins, thus formaldehyde
forms schiffs bases. So the protein is irreversibly modified.
Also, yes, casein is edible... what do you think cheese is made of?
I'd be interested to hear about this hodges. It should work in theory. YOu could also try ibuprofen, or paracetamole. They both may produce plastics.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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Nicodem
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| Quote: | | YOu could also try ibuprofen, or paracetamole. They both may produce plastics. |
Not Ibuprofen. It is not a phenol and it does not form any polymer with formaldehyde.
Paracetamol should do, but it will probably form more like a gelatinous polymer and not really plastic like bakelite. It would be due to the hydrophilic amide groups and the even more polar N-hydroxymethyl-amide groups that will form with the interaction
with HCHO.
Perhaps it can be hardened if heated for a while since a crosslinking can happen (for example, of the type 2Ar-N(CH2OH)-Ac -> Ar-N(Ac)-CH2-N(Ac)-Ar
+ HCHO)
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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hodges
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Neither Aspirin Compund Worked
I tried making a plastic using both acetylsalicylic acid and salicylic acid with formalin. Neither one produced any plastic.
I purified some generic aspirin by dissolving them in 90% warmed isopropyl alcohol, filtering, and precipitating the crystals using cold water. After
drying, I took 0.5g of the purified ASA and added a few ml of formalin solution. Upon adding a ml or so of concentrated NaOH solution, the mixture
heated up strongly, boiling briefly. But there was no plastic formed. In fact, the mixture, which had beens sort of white (maybe because the ASA was
not completely dissolved) instead became clear. I repeated the experiment using several drops of HCl instead of NaOH as a catalyst. The solution did
not heat up ,and it remained write.
Next I heated the ASA in 20% HCl. After a few minutes the mixture thickened with a dense jelly-like crystals. I continued heating for 30 minutes,
then cooled and dumped in ice water. I filtered the precipitate and washed with ice water, then squeezed out the excess water. The resulting
salicylic acid had a consistency like that of mush. I didn't let it finish drying but I was able to squeeze most of the water out of it. I repeated
the above experiment using the SA. Results were the same, except that there was not as much heating when adding the NaOH solution. When treated with
NaOH the solution remained white. When treated with even a few drops of HCl the solution became totally clear.
I took a small amount of the ASA, dissolved in excess water, and added a drop ferric chloride solution (PC board etching chemical). The solution
turned slightly orange, possibly just the color from the ferric chloride. This indicates a negative test for phenol. I repeated the test with SA and
I got a very intense purple precipitate that was almost black until diluted. That is a positive test for phenol.
I'm not sure why I got so much heating with the NaOH and ASA/formalin but not with NaOH/SA/formalin. Only thing I can think of is that it could have
just been a neutralization reaction with the acetyl group, which is present in ASA but not SA. It looks like the salicylate interferes with the
plastic that would be formed using plain phenol. Or else I need a different catalyst than would be used with phenol.
Hodges
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sparkgap
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hodges, did you use excess NaOH? I've the feeling that only neutralization occured if you used an amount of base less than the molar amount of SA/ASA
you used.
I want to see pictures of homemade crosslinked (w/ formaldehyde) casein. 
sparky (^_^)
[Edited on 18-7-2006 by sparkgap]
[Edited to remove reference to (now deleted) trolling earlier in thread]
[Edited on 18-7-2006 by I am a fish]
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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hodges
National Hazard
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Phenol-Formalin - I Found This
Apparently a lot more is required than simply mixing things together. This is from Vogel Practical Organic Chemistry (3rd edition p1023):
| Quote: |
Place a mixture of 25 g. of phenol, 50 ml. of formalin and 3 ml. of 40 per cent. sodium hydroxide solution in a 500 ml. conical flask. Attach a
reflux condensor to the flask and reflux gently. As the heating proceeds, the mixture acquires a red coloration and becomes increasingly more
viscous. After 60-75 minute the contents of the flask are so viscous that the bubbles which rise through the mass encounter great difficulty in
escaping from the surface. At this point remove the flame and immediately pour the viscous mass into a wide test tube ("boiling tube"); upon cooling
an opaque white solid is obtained. To complete the preparation, place the "boiling tube" in an air oven for 1 hour at 50 degrees and 4 hours at 60-75
degrees; when the "baking" process is complete a hard pink mass of plastic is obtained.
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Hodges
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The_Davster
A pnictogen
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Wow...more complicated than the procedure when using resorcinol
"Add 5ml formalin to the resorcinol(2g) in a vial. Replace cap on vial. Swirl until dissolved.
Add 3mL of 10% KOH solution(catalyst). Do not replace the cap(the solution heats up).
The liquid will solidfy in several minutes. A penny can be embedded in the plastic."
EDIT: I posted a picture of this a couple years ago in a similar thread, completly forget the name though.
[Edited on 19-7-2006 by rogue chemist]
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Rosco Bodine
Banned
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I have some old patent references which may be interesting concerning various urea - formaldehyde condensation products and related formulations which
have various uses as plasticizers , films , and thermosetting resins .
GB171094
GB368027
GB320915
GB521380
GB193420
GB151016
GB181014
GB157416
GB266752
GB949635
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