Draeger
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Distinguishing plastics without analysis?
So, I have some plastic test tubes laying around that I bought a very long time ago, and I have no idea out of which plastic they are made.
Is there any way to find out without chemically analyzing them?
[Edited on 14-3-2020 by Draeger]
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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UC235
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Yes, there's only a few common plastics used for this sort of thing and they have different physical properties. Without even looking, my guess would
be polypropylene which is widely used for plastic lab disposables.
What do they look like? Are they opaue, hazy and translucent, or clear? Are they hard and "glassy" or do they have give to them?
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Draeger
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Quote: Originally posted by UC235  | Yes, there's only a few common plastics used for this sort of thing and they have different physical properties. Without even looking, my guess would
be polypropylene which is widely used for plastic lab disposables.
What do they look like? Are they opaue, hazy and translucent, or clear? Are they hard and "glassy" or do they have give to them?
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Here's a picture of one of them.
They also have a very opaque, blue cap, similar to the cap of the water bottle in the picture.
The test tube itself feels hard, but it definitely doesn't act like glass. It is much more stable, and I could probably only break it by hitting it
with a hammer or doing something of similar or greater force. The tip, on the other hand, has elastic properties and you can bend it with some force
without it breaking or permanently being changed.
[Edited on 14-3-2020 by Draeger]
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Deathunter88
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Looks like polycarbonate to me, can you send a clearer picture.
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Draeger
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Here's a clearer one. Might also be slightly corroded by ethanol I had in it for years when I didn't know ethanol ate some plastics.
[Edited on 15-3-2020 by Draeger]
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Heptylene
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It could also be polystyrene or PET. If you can afford to destroy one, try smashing it. It it shatters easily it's likely to be polystyrene.
Polycarbonate is impact resistant and won't shatter. PET won't shatter either.
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Draeger
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Posts: 185
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Location: North-Rhine Westfalia, Germany
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Mood: Slowly getting ready for new projects
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| Quote: Originally posted by Heptylene | | It could also be polystyrene or PET. If you can afford to destroy one, try smashing it. It it shatters easily it's likely to be polystyrene.
Polycarbonate is impact resistant and won't shatter. PET won't shatter either. |
Since they were visibly corroded by the ethanol and they looked like hitting them with a hammer would break them, I very much assume that it is
polystyrene. Thank you all for your help.
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Morgan
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Maybe see how a small spot on the tube reacts with acetone if you think it's polystyrene.
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TheMrbunGee
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These are polystyrene. Have had too many incidents with acetone, I can now tell by the look, at least out of several common ones.
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UC235
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Acetone will trash polystyrene. You could also heat it with a torch. The smell of styrene is unmistakable.
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yobbo II
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Could be perspex (metamethcrylate?)
Poly(methyl 2-methylpropenoate)
Yob
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DavidJR
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I think that's almost certainly polystyrene. IMO polystyrene containers are basically trash and should be avoided.
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