Sciencemadness Discussion Board - phenophthalein

phenophthalein

CrossxD - 6-7-2015 at 08:36

Is there way to make phenol from polystyrene and phthalic acid from PET, acetylsalicilic acid or benzene from household thinks??

Thanks for reply.

blogfast25 - 6-7-2015 at 08:51

Quote: Originally posted by CrossxD

Is there way to make phenol from polystyrene and phthalic acid from PET, acetylsalicilic acid or benzene from household thinks??

Thanks for reply.

Phthalic can be extracted from vinyl (pPVC) gloves, shower curtains and other soft PVC items (there are several threads on this forum about that).

Not from PET, which is a TEREphthalate.

[Edited on 6-7-2015 by blogfast25]

Praxichys - 6-7-2015 at 08:55

1. Phenol can be made by heating acetylsalicylic acid
2. Benzene can be made by heating NaOH and sodium benzoate
3. p-phthalic acid can be made by hydrolyzing PET ester with NaOH in ethylene glycol

You need m-phthalic acid for the phthalic anhydride needed for phenolphthalein condensation using phenol. You also need a strong lewis acid to catalyze the reaction.

Metacelsus - 6-7-2015 at 09:07

Phenol from salicylic acid:

https://www.sciencemadness.org/whisper/viewthread.php?tid=27...

Phthalates from plastic:

http://www.sciencemadness.org/talk/viewthread.php?tid=25567#...

gdflp - 6-7-2015 at 09:48

Quote: Originally posted by Praxichys

You need m-phthalic acid for the phthalic anhydride needed for phenolphthalein condensation using phenol. You also need a strong lewis acid to catalyze the reaction.

Only ortho-phthalic acid can form a cyclic anhydride, m-phthalic acid cannot easily. Phenolphthalein is synthesized by condensing phthalic anhydride(from dehydrating o-phthalic acid) with phenol and an acid catalyst.

[Edited on 7-6-2015 by gdflp]

CrossxD - 6-7-2015 at 10:10

Thank you very much, but what shower curtains have phthalic esters, how they look?

UC235 - 6-7-2015 at 10:25

Quote: Originally posted by CrossxD

Thank you very much, but what shower curtains have phthalic esters, how they look?

Soft, clear plastic that smells bad in most cases. Don't bother with shower curtains. My experiments found that they only contain ~10-15% plasticizer. Vinyl gloves contain approximately 30% and are a much more viable source.

CrossxD - 6-7-2015 at 10:37

In my country are gloves made only from latex...:/
Only in pharmacy but they are expensive

CrossxD - 6-7-2015 at 11:14

Isn't strong lewis acid sulphuric acid?

blogfast25 - 6-7-2015 at 12:03

Quote: Originally posted by UC235

Don't bother with shower curtains. My experiments found that they only contain ~10-15% plasticizer. Vinyl gloves contain approximately 30% and are a much more viable source.

Hmmm... garbage shower curtain, garden hose, vinyl flooring etc contain less DOP but it will cost you less and you can get MORE if you're willing to scale up a bit.

aga - 6-7-2015 at 13:13

Quote: Originally posted by CrossxD

Isn't strong lewis acid sulphuric acid?

The definition of what is a Lewis Acid is a bit different to what you might naturally assume.

https://en.wikipedia.org/wiki/Lewis_acids_and_bases

CrossxD - 7-7-2015 at 05:30

what are best solvents for phthalic esters?

blogfast25 - 7-7-2015 at 08:18

Quote: Originally posted by CrossxD

what are best solvents for phthalic esters?

Most lower alcohols are fine: MeOH, EtOH, IPA.

CrossxD - 8-7-2015 at 05:47

I found video where p. acid was made by oxidation o-xylene
is possible to separate xylene isomers?

Praxichys - 8-7-2015 at 06:09

Quote: Originally posted by gdflp

Quote: Originally posted by Praxichys

You need m-phthalic acid for the phthalic anhydride needed for phenolphthalein condensation using phenol. You also need a strong lewis acid to catalyze the reaction.

Derp. My bad. 1,2-benzenedicarboxylic acid. Kind of embarrassing to get o- and m- mixed up at this point.

CrossxD - 13-7-2015 at 07:37

I recrystallized some acetylsalicylic acid and if I want to make from it salicylic acid I must reflux it with hydrochloric acid righ? Or I can leave it for about day still?

Texium - 13-7-2015 at 08:38

Quote: Originally posted by CrossxD

I recrystallized some acetylsalicylic acid and if I want to make from it salicylic acid I must reflux it with hydrochloric acid righ? Or I can leave it for about day still?

Refluxing with 15% hydrochloric acid for a couple hours is your best bet. As you cool the solution, the change will be obvious, as a ton of fluffy, needle-like crystals of salicylic acid will fall out which look very different from ASA.
Boiling it in water would also work, but is a lot slower and less efficient.

gdflp - 13-7-2015 at 08:44

Refluxing with 15% HCl for hours is excessive. A reflux with very dilute HCl for a half hour will give a nearly quantitative yield of salicylic acid. UnintentionalChaos described this procedure here. I have successfully replicated it several times with a slight modification.

CrossxD - 13-7-2015 at 08:47

and is better to use base ester hydrolysis or acid ester hydrolysis???

Texium - 13-7-2015 at 08:51

Quote: Originally posted by gdflp

Refluxing with 15% HCl for hours is excessive. A reflux with very dilute HCl for a half hour will give a nearly quantitative yield of salicylic acid. UnintentionalChaos described this procedure here. I have successfully replicated it several times with a slight modification.

Sorry, I know it is. I like being through.

gdflp - 13-7-2015 at 10:02

Quote: Originally posted by CrossxD

and is better to use base ester hydrolysis or acid ester hydrolysis???

Acid hydrolysis is, IMO, less wasteful in respect to both chemical usage as well as time.

CrossxD - 25-8-2015 at 10:20

is acetone good solvent for phthalic esters?

Oscilllator - 25-8-2015 at 17:49

Quote: Originally posted by CrossxD

is acetone good solvent for phthalic esters?

Yes, but You shouldn't use it for the extraction of them as PVC is highly soluble in acetone. They actually use it in conjunction with butanone to weld PVC pipes. I used methylated spirits and the extraction went fine for me.

CrossxD - 28-8-2015 at 06:09

and what about make phthalic acid by oxidation xylen with hydrogen peroxide with some alkali hydroxide?

[Edited on 28-8-2015 by CrossxD]

blogfast25 - 28-8-2015 at 07:32

Quote: Originally posted by CrossxD

and what about make phthalic acid by oxidation xylen with hydrogen peroxide with some alkali hydroxide?

[Edited on 28-8-2015 by CrossxD]

The only oxidation of ortho-xylene to phthalic acid that I know of is by means of potassium permanganate. 'UC235' has a very good YouTube video on that synthesis:

https://www.youtube.com/watch?v=PAARYmBYudg

Hydrogen peroxide would not have the oxidising power needed, I think.

[Edited on 28-8-2015 by blogfast25]