| Pages:
1
2 |
hodges
National Hazard
Posts: 525
Registered: 17-12-2003
Location: Midwest
Member Is Offline
|
|
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?
|
|
|
Mr. Wizard
International Hazard
Posts: 1042
Registered: 30-3-2003
Member Is Offline
Mood: No Mood
|
|
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
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
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. 
[Edited on 26-9-2004 by vulture]
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
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...
I will try to dig it up, it is in the lab somewhere.
|
|
|
chemoleo
Biochemicus Energeticus
Posts: 3005
Registered: 23-7-2003
Location: England Germany
Member Is Offline
Mood: crystalline
|
|
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!
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
|
|
|
kyanite
Hazard to Self
Posts: 86
Registered: 30-6-2004
Location: is not important!
Member Is Offline
Mood: lactamic
|
|
Are all polymers plastic like?
Question: Are all polymers plastic like?
Because if so...
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!
What do you guys think?
Edit: damn quotes...
[Edited on 27-9-2004 by kyanite]
|
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
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.
|
|
|
BromicAcid
International Hazard
Posts: 3245
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
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...
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
| 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!
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
| 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.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
TheBear
Hazard to Self
Posts: 78
Registered: 17-10-2002
Location: Sweden
Member Is Offline
Mood: distilled
|
|
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)?
|
|
|
garage chemist
chemical wizard
Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
TheBear
Hazard to Self
Posts: 78
Registered: 17-10-2002
Location: Sweden
Member Is Offline
Mood: distilled
|
|
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).
|
|
|
garage chemist
chemical wizard
Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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]
|
|
|
Mr. Wizard
International Hazard
Posts: 1042
Registered: 30-3-2003
Member Is Offline
Mood: No Mood
|
|
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?
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
mick
Hazard to Others
Posts: 338
Registered: 3-10-2003
Member Is Offline
Mood: No Mood
|
|
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]
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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]
|
|
|
hodges
National Hazard
Posts: 525
Registered: 17-12-2003
Location: Midwest
Member Is Offline
|
|
| 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
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Tacho
National Hazard
Posts: 582
Registered: 5-12-2003
Member Is Offline
Mood: No Mood
|
|
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]
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
