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Author: Subject: Homemade Plastics?
hodges
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[*] posted on 26-9-2004 at 07:19
Homemade Plastics?


Is it possible to make plastics starting with (say) cellulose such as cotton? I recently nitrated some cotton and dissolved in acetone. After the acetone evaporated, what remained was a substance that (when thin) looked like clear plastic. I was wondering if it might also be possible to create other plastic-like substances (not necessarily pyrotechnic) from cotton at home. I believe besides cellulose nitrate there is cellulose acetate which is a plastic, right? Could this be made at home. What about other plastic-like compounds?
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Mr. Wizard
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[*] posted on 26-9-2004 at 07:48


Here is an old one, Rayon. This site describes two ways of making it. The cupro-ammonium method can be made in the kitchen.
http://www.fibersource.com/f-tutor/rayon.htm
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vulture
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[*] posted on 26-9-2004 at 08:00


I once made nitrocellulose using nitric acid (70%) and phosphoric acid (85%).

When I left the product in a beaker with acetone to evaporate, I found an O-ring of plastic foil with the diameter of the beaker and a width of about 4 inches. It was perfectly clear, flexible and quite tear resistant.

I impressed the hell out of my grade 6 chemistry teacher with that. :D

[Edited on 26-9-2004 by vulture]




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Tacho
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[*] posted on 27-9-2004 at 05:12


If you have acess to formaline (formaldehyde solution), it forms polymers with urea, phenol or resorcin. If memory serves me well, if you mix formaline solution with a urea solution in water, a white mass is formed, somewhat like plaster of paris. Not very resistant though, after all, it's soaked with water.

Formalin is linked to cancer. Check the risks first.
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[*] posted on 27-9-2004 at 14:34


I have done the reaction of formalin with resorcinol once. It produces a red plastic. This was a while ago so i do not remember concentrations but 2g of resorcinol was dissolved in 10(?) mL of x% formalin solution then either 5 or 10 mL of 30% KOH solution was added. It solidifies to a red solid in under 5 min.

I stuck a penny in it...:P
I will try to dig it up, it is in the lab somewhere.
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chemoleo
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[*] posted on 27-9-2004 at 14:41


Doing the formalin (34%) and urea experiment yielded in my case a soft squishy white mass. I guess this might work better with pure formaldehyde. Would paraformaldehyde work better, I wonder? get the reaction kick-started with a drop of dilute acid?

Anyway - another I always dreamed of making is polyethylene.
Ethylene (ethene) is actually just fed into a vessel with TiCl4 IIRC, and the PE deposits as granules. I don't remember the solvent. A long time ago I read this, but I remember trying to get hold of TiO2 at the time (when I didn't know of pottery supplies)...

Another is of course to decompose polystyrene, and distill off the mono-molecular styrene.
This, if left alone, reacts after some time by itself, to form PS again. Otherwise, the distillate can be poured into a mold, a drop of MEKP/benzoylperoxide is added, and a few minutes later the PS cast can be removed!




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[*] posted on 27-9-2004 at 15:12
Are all polymers plastic like?


Question: Are all polymers plastic like?

Because if so...:D

http://ptcl.chem.ox.ac.uk/MSDS/AC/acrolein.html

http://www.inchem.org/documents/ehc/ehc/ehc127.htm

[Quote]
Stability
Stable, but very readily polymerizes. May have ca. 0.1% hydroquinone added as stabilizer. Flammable. Incompatible with oxidising agents, reducing agents, oxygen, a variety of other chemicals, light. Very reactive with a wide variety of chemicals. May polymerize violently, especially on contact with strong acids or bases.
[/Quote]

Sounds easy enough ;)

[Quote]
In the absence of an
inhibitor, acrolein is subject to highly exothermic polymerization
catalysed by light and air at room temperature to an insoluble,
cross-linked solid. Highly exothermic polymerization also occurs in
the presence of traces of acids or strong bases even when an
inhibitor is present. Inhibited acrolein undergoes dimerization
above 150 °C.
[/Quote]

Toxic, low boiling point, easily flamable starting material, with a -18 degrees flash point...

Sounds fun!:D

What do you guys think?

Edit: damn quotes...

[Edited on 27-9-2004 by kyanite]
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[*] posted on 27-9-2004 at 19:13


Here is the pic of the resorcinol/formalin plastic with the penny.

Its on the goggles because I could not find a clean spot on my lab table as I am in the process of a bit of reorganising.

penny in plastic.bmp - 900kB
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[*] posted on 27-9-2004 at 19:18
On the early nitrocellulose plastics....


Quote:
The discovery of the first man-made plastic has often been credited to the English chemist and inventor, Alexander Parkes. Parkes discovered Parkesine, later known as Xylonite, which is actually nitrocellulose (or pyroxylin) treated with vegetable oil and a little camphor, in 1862. However, the plasticizing effects of certain solvents on nitrocellulose was actually discovered in the 1840s by a French revolutionary poet and painter, Louis Ménard, who used a combination of ether and alcohol as a solvent, and called his substance ‘collodion’. Ménard quickly lost interest in the substance, however, when he found that it could not be used as a varnish for paintings, as he could see no other use for the substance. It was collodion, however, which captured Parkes’ interest as a plausible ‘plastic mass’, a material that could be molded and cast into an infinite number of identical objects by machine, and could challenge the dominance of the rubber companies and their vulcanized rubber. However, the solvent originally used to make collodion was too expensive, so Parkes used a cheaper substitute of vegetable oils. Hence, Parkes’ attempts to market his material failed miserably as he compromised the quality of his goods for lower costs of production. From the very beginning, the cost of plastic and the quality of the material were significant in the marketing and viability of plastic.

John W. Hyatt and the Camphor Solvent

The commercial success of the first plastic can be attributed to John W. Hyatt. In the mid-1860s, billiard balls were becoming increasingly expensive due to the increasing demand for billiard balls, and the difficulty of manufacturing billiard balls from ivory. In the process of searching for a substitute, a bottle of spilled collodion gave Hyatt the inspiration of using collodion as a coating for billiard balls. While the resulting billiard balls were a dismal failure, it was through his efforts at billiard ball manufacture that Hyatt discovered that camphor is actually a much more suitable solvent for nitrocellulose than those previously used, and coined the new material ‘celluloid’, which was the first thermoplastic – a moldable mass formed by heat and pressure into a shape that it retains even after the forces that shaped it have been removed. With this new thermoplastic which could be easily molded by mechanized methods of mass production, coupled with successful marketing and the investment of a group of New York investors, led by Gen. Marshall Lefferts, Hyatt achieved considerable success in challenging the rubber monopoly. However, celluloid still tended to yellow and crack over time, and it had another, more dangerous defect: it burned easily and spectacularly, unsurprising given that mixtures of nitric acid and cellulose are also used to synthesize smokeless powder.


Text quoted from: http://staff.science.nus.edu.sg/~parwani/htw/htwproject2/pla...




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[*] posted on 28-9-2004 at 03:56


Quote:
Originally posted by chemoleo
Doing the formalin (34%) and urea experiment yielded in my case a soft squishy white mass. I guess this might work better with pure formaldehyde. Would paraformaldehyde work better, I wonder? get the reaction kick-started with a drop of dilute acid?


Yes, I think acid was used to start the reaction!

Urea gave that white mass that, if I remember right, dries to a more solid thing, but shrinks a lot. Phenol gave a sticky amber goo, that solidified with time and heat, and resorcinol gave an amber solid. But the details have long sliped away from my memory...

Epoxy and polyester have filled all my homemade plastic needs for many years. Polyurethane is my new toy. One can get all this and many other interesting things in fiberglass supply shops. I even found aluminum powder in one of them!
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[*] posted on 28-9-2004 at 09:44


Quote:

Anyway - another I always dreamed of making is polyethylene.


Forget it. PE needs absolute moisture free environment. Slightest trace of H2O and it will fail.




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[*] posted on 28-9-2004 at 10:20


Just a little dumb question:

I always wondered wheter one could make a polyester from oxalic acid and ethylene glycol? Would a simple condensation yield a polymer? And if so: would it be stable (not hydrolyse if it's exposed to water)?
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[*] posted on 28-9-2004 at 10:37


I have a detailed laboratory synthesis of polyethylene that doesn't need pressure.

It uses a special catalyst. It consists of a mixture of Amyllithium and TiCl4 in petrolether.

The synthesis takes very laborous steps to make sure that everything is not only absolutely anhydrous, but also free of oxygen (working under nitrogen atmosphere, refluxing the petrolether under nitrogen before use, purifying the nitrogen and ethylene).

If there's interest, I could outline the synthesis.

@TheBear: why don't you try it out? Mix some ethylene glycol and oxalic acid and heat it! I also don't know if it would work, but I would at least try it out.
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[*] posted on 28-9-2004 at 10:55


You're right. This ought to be done. I'll report back with results when oxalic acid has been aquired.

(I'm not lazy it's just that I've only got ~10 ml of H2SO4 which I've worked a couple of hours to get, would be a pain to waste it on something that doesn't work).
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[*] posted on 28-9-2004 at 11:01


You only need a few drops of H2SO4 at max!

Maybe it also works without H2SO4. Try that before, and if it doesn't work, use only a few drops.
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[*] posted on 6-10-2004 at 03:31
Not exactly homemade but...


Ricin oil reacts with isocyanates to produce a polyurethane plastic. You mix both and it hardens overnight. I tried with industrial isocyanate, but you can find isocyanate in fiberglass supply shops as one of the components (the dark one) of bi-component polyurethane foam. This probably works.

I tried to mix paraformaldehyde with ricin oil. Although the paraformaldehyde did not dissolve in the oil, it does seem to thicken overnight. Maybe given more time... Does anybody know an organic solvent that can dissolve lots of paraformaldehyde?

[Edited on 6-10-2004 by Tacho]
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Mr. Wizard
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[*] posted on 6-10-2004 at 14:18


Is "Ricin Oil" the same as Castor Oil, the oil extracted from Castor Beans and used as a lubricating oil in model engines and race cars?
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[*] posted on 6-10-2004 at 18:02


Yes. Its principal ingredient, 85%, is the triglyceride of ricinoleic acid, cis-CH3(CH2)5CH(OH)CH2CH=CH(CH2)7COOH. It also has other C-18 acids, oleic (8%) and linoleic (4%) and stearic (1%, the only major saturated acid present), and 2% others (which are probably C-20 and C-16). This is according to McMurry's Organic Chemistry.

John W.
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[*] posted on 7-10-2004 at 02:59


Just an extra note on ricin (castor) oil and isocyanates: after 24 hours , some bubbles develop in the mass. There must be a way to circunvent this, since there are many studies on ricin oil polymers for medical implants.
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[*] posted on 7-10-2004 at 11:42


Isocyanates
They are used for making plastics.
As far as I am aware, they are the best sensitizers known to man.
I have know a few people that have used these with out being careful.
The one person nearly had kidney failure,
the other person had a collapsed lung ( and had to have a medical to check his breathing every year), the other person was covered in scabs every time he came close to an isocyanate.
A friend of mine works in a place that uses toluene di-isocanate and if there is any problem an alarm goes off. After that it is full body kit.
I do not know how they work, but I am very wary of isocyanates
mick

add the y

[Edited on 7-10-2004 by mick]
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[*] posted on 7-10-2004 at 22:58


Remember that leak at the Union Carbide chemical plant in Bhopal, India (built there as the result of "outsourcing";), several years ago. It resulted in 3,000 people being poisoned to death and many others injured by methyl isocyanate, CH3-N=C=O. It was being used as an intermediate in the manufacture of pesticides.

John W.
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[*] posted on 8-10-2004 at 04:27


Methyl isocyanate is a very nasty chemical indeed. And all polyurethanes release nasty gasses when they decompose thermically (catch fire).

Although the isocyanates commonly sold for polyurethane making are in the PREPOLYMER form (usually from TDI or MDI) and are far less hazardous than methyl isocianate, stay away from any chemical unless you know exactly all the risks involved!!

I apologize for posting without fully warning the hazards involved.

The ricin plant also has one of the most powerfull toxins known to man. So it may kill you easily.

The ricin oil can cause serious gastrointestinal upseting.

Wear googles and gloves.

Toxicology of the ricin plant.

Edit: And formaldehyde causes CANCER!

Death everywhere!

[Edited on 8-10-2004 by Tacho]
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[*] posted on 13-7-2006 at 16:08


Quote:
Originally posted by Tacho
If you have acess to formaline (formaldehyde solution), it forms polymers with urea, phenol or resorcin. If memory serves me well, if you mix formaline solution with a urea solution in water, a white mass is formed, somewhat like plaster of paris. Not very resistant though, after all, it's soaked with water.

Formalin is linked to cancer. Check the risks first.


I now have formalin. I wonder if it would be possible to use something made from aspirin in place of the phenol? I know the acetyl group can be removed from aspirin easily enough by adding dilute H2SO4. Would that be good enough or is it necessary to go all the way to phenol in order to get a plastic with formalin?

Hodges
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[*] posted on 14-7-2006 at 10:25


I don't know.

I think you should give it a try. Sounds simple.

Formalin renders gellatin and other proteins insoluble, if it's a crosslinking process, the insoluble gellatin would be a plastic wouldn't it?.

I have made pieces of insoluble gellatin by mixing the hot liquid gellatin with formalin and waiting for it to cool. Also by imersing pieces solid gelatin in formalin. The pieces will not melt on re-heating. After it dries, it remains transparent and insoluble, although it shrinks a lot, of course.

The pieces smell strongly of formaldehyde and therefore pose a health threat. Maybe someone in this forum would have a good sugestion to neutralize the formaldehyde.




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[*] posted on 14-7-2006 at 16:00
Casein!


Talking about formalin rendering proteins insoluble, how could I forget to mention CASEIN in this thread!

Casein was one of the first "plastics" made and all you need to make at home it is milk, some acid and some base. Oh, and formalin to make it insoluble.

Warm 50ml of nonfat milk (zero fat if possible) to about 40-45 degrees celsius, remove the flask from the heat and, while stirring, ad dropwise an aqueous solution of acetic acid 10% (or simple vinegar) until no further precipitation is observed. That is about 4ml of vinegar or 2ml of GAA 10%. Pass the mass through a sieve to retain the curd.

The curd is now a white mass that becomes soluble in water and more transparent when you basify it. Ammonia solution is the best, because ammonia evaporates along with the water leaving pure solid casein behind, as a transparent plastic. Baking soda also works, but the results are less impressive. Try ammonia if you can get some.

To render the casein insoluble, mix some formalin with it before it dries or immerse the dry pieces in it.

Edit:

note1- Casein is clear and transparent in thin pieces, but thick pieces may look darker. I remember reading about procedures to purify it and hence make it lighter, but I never tested them.

note2- Casein is an organic protein, and therefore is prone to be atacked by bacteria and/or fungi. Actually, it's edible as far as I know. Formalin probably makes it more resistant, since it's poisonous.



[Edited on 15-7-2006 by Tacho]




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