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Author: Subject: Borax and PVA
NEMO-Chemistry
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[*] posted on 12-9-2016 at 11:29


Quote: Originally posted by aga  
What will 'working' be ?

A rubbery thing ?


Original idea was i wanted a thin membrane, this isnt going to happen with PVA.

So plan B seeing as i have the glue is a rubbery thing and slime, not as dopey as it seems because Halloween isnt far off :/.

Seriously though what i wanted was a simple starting point for learning about polymers, i thought this would be ideal.......
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[*] posted on 12-9-2016 at 12:10


The 'usual' way is to find a publication that gets at least near what you want, then tweak it a little.

Cuts out all the 'i wonder if' stuff at the beginning.




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[*] posted on 12-9-2016 at 13:14


Quote: Originally posted by aga  
The 'usual' way is to find a publication that gets at least near what you want, then tweak it a little.

Cuts out all the 'i wonder if' stuff at the beginning.


I have been following some papers and some websites, the problem appears to be in the naming of PVA.

Now i am reading a few more and it looks like the white glue will work but requires a different amount of Borax and slightly different different conditions.

At the moment my best plan is to read more papers and delve a bit deeper, i dont assimilate the information very quickly as alot of it is new concepts for me.

I apologize for the delay but reading and then understanding what i have read takes me a little time.

Once i have found some information i can follow i will post up here, I did have a go tonight at trying a few things out, i got mixed results.

I am pretty sure the white Polyvinyl Acetate glue will work to some extent, i am also sure it can be modified (all from reading).

The question's are now

1) is it worth trying to get the white Acetate to work?

2) If i get the white Acetate to work will it give me results i am happy with?

The Answer to one is, probably worth a shot if only for the learning and understanding what i read and then putting into practice.

The answer to 2 is likely to be No.

Tomorrow i want to concentrate on getting some noob questions finished and read up some more. But i will be doing some more research on this polymer.

I kind of have an end goal, but i would rather see it through and find the answer by reading and experimenting, rather than just ask and get the answer.

Hopefully people will understand why sometimes reinventing the wheel helps you learn how a wheel works :D.


Edit

Just to make my life easier i will post up some of the papers i came accross and will work from.

The first details both slime (Alcohol) and Gluep (Acetate)



[Edited on 12-9-2016 by NEMO-Chemistry]

Attachment: slimesandgluep.pdf (155kB)
This file has been downloaded 106 times

Not sure about this one, it might help with the Hydrolysis of the glue, a quick read makes me think i have to sit down and really read it properly.



[Edited on 12-9-2016 by NEMO-Chemistry]

Attachment: preparing pva from glue.pdf (87kB)
This file has been downloaded 100 times

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[*] posted on 12-9-2016 at 15:11


From the last link above, here is the procedure for the hydrolysis of the partially acetylated alcohol which they call aqueous glue.

"A solution mixture containing about 30 g of the aqueous
PVA glue in 100 mL of water and 10 mL of 2 M NaOH
is heated to a gentle boiling on a hot plate with continuous
stirring for about 25 minutes. After the reaction, the product
is precipitated in a saturated NaCl solution. The resulting
polymer is removed from the solution with a glass stirring
rod and washed with large quantity of water. Subsequently,
part of the PVA product is dissolved in water to form a viscous solution."

In the notes of the same paper:

"1. In Taiwan, as in the United States, most of the aqueous
PVA glues contain PVA with residual acetate groups. Five different aqueous PVA glues purchased from stores in the United States (clear Elmer’s washable school glue, MonoAqua liquid glue, Staples liquid glue, Dab’N Stic paper glue, and Pentel brush glue) were tested in this experiment and gave similar results.

2. In this experiment, white glue is not used for the preparation of PVA because polyvinyl acetate is much more difficult to be hydrolyzed in aqueous solution. We have tried the hydrolysis in ethanol using strong base as the catalyst. A barely complete hydrolyzed PVA was obtained by refluxing the mixtures of 10 g of white glue and 2.6 g KOH in 100 mL of ethanol for 2.5 hours."

I guess its more difficult to hydrolyze the emulsion of polyvinyl acetate because it not soluble in water.
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[*] posted on 12-9-2016 at 15:24


Hi,

Perhaps some of the confusion is in the nomenclature. PVA can mean Polyvinyl Acetate OR Polyvinyl ALCOHOL. The alcohol is sometimes listed as PVOH.

I've made the borax cross linked material with PVOH.

You may wish to read this monograph.

Attachment: phpICT9ma (2MB)
This file has been downloaded 106 times

Hope this helps.
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[*] posted on 12-9-2016 at 16:27


Quote: Originally posted by wg48  
From the last link above, here is the procedure for the hydrolysis of the partially acetylated alcohol which they call aqueous glue.

"A solution mixture containing about 30 g of the aqueous
PVA glue in 100 mL of water and 10 mL of 2 M NaOH
is heated to a gentle boiling on a hot plate with continuous
stirring for about 25 minutes. After the reaction, the product
is precipitated in a saturated NaCl solution. The resulting
polymer is removed from the solution with a glass stirring
rod and washed with large quantity of water. Subsequently,
part of the PVA product is dissolved in water to form a viscous solution."

In the notes of the same paper:

"1. In Taiwan, as in the United States, most of the aqueous
PVA glues contain PVA with residual acetate groups. Five different aqueous PVA glues purchased from stores in the United States (clear Elmer’s washable school glue, MonoAqua liquid glue, Staples liquid glue, Dab’N Stic paper glue, and Pentel brush glue) were tested in this experiment and gave similar results.

2. In this experiment, white glue is not used for the preparation of PVA because polyvinyl acetate is much more difficult to be hydrolyzed in aqueous solution. We have tried the hydrolysis in ethanol using strong base as the catalyst. A barely complete hydrolyzed PVA was obtained by refluxing the mixtures of 10 g of white glue and 2.6 g KOH in 100 mL of ethanol for 2.5 hours."

I guess its more difficult to hydrolyze the emulsion of polyvinyl acetate because it not soluble in water.


I didnt save the link and dismissed the information(probably a mistake), but i think i read information alluding to adding HCl to make the white acetate soluble..

I need to be more careful when reading stuff and how i organize it!

If nothing else getting to the bottom of this and trying a few things out will be good practice, even a fail would be useful in some respects.
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