Pages:  1  2 Author: Subject: Borax and PVA Borax and PVA


I am trying out the polymer experiment with PVA glue and borax to make the poor mans 'flubber'.

I have u2ed aga to see if he would copy this and rack the product on his stretcher he made for the commercial stuff.

My question though is..

What else apart from Borax can i use with PVA to make a polymer? I am trying to see how it compares with polymers like the one they tried out on the rack.

The Borax/PVA experiment is common, but i wondered if any other polymers could be made with PVA?

Erm, doesn't the 'P' part of PVA stand for polymer ?

Sure i'll copy your synth, when documented/posted and stretch it to bits.

With data.

Edit:

What kind of stretchy-snappy-o-meter owner wouldn't ?

[Edited on 8-9- by aga]

Link to ruyuan

To answer your question NEMO, you need to know what is happening with the borax to form the cross-linking. In all honesty, I forget the details but it is googleable. There are undoubtedly plenty of other cross-linking agents but borax happens to be particularly accessible.

If you are trying to duplicate the experiment elsewhere in the world you need to be aware that not all PVA is the same. The composition -- and in particular the water content does vary a lot. The polymer chain length and the amount of branching present is also likely to be different. This makes duplication difficult -- unless you send aga some bottles of your reagents. And even then, it is 42°C in aga's shed and -3 in Scotland. Reproducibility is an issue.

I was kind of interested in how the stuff compares with the other polymer he racked. So i figure for that any PVA will do as long as he uses the same brand each time.

When i get home i will dig up the info from the Royal society where i saw the experiment.

I have seen PVA described as Poly Vinyl Alcohol and Poly Vinyl Acrylate, so i am not too sure what it actually stands for!



This is the first one

http://www.rsc.org/learn-chemistry/resource/res/pva-...

There is also one using PVA to make a harder polymer, i will track that down again.

From memory the RSC one is more of a slime than something to stretch. I will find the other one but it mostly comes down to how much Borax you add (up to a point), add too much and it breaks down again.

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

Quote: Originally posted by NEMO-Chemistry  mostly comes down to how much Borax you add (up to a point), add too much and it breaks down again.
Doesn't sound too hard to find out how much ... let's see ...

A little bit left field but, having read a couple of papers it looks like various versions of PVA with formaldehyde and other additives have been used in medicine.

One use is for a temporary skin covering for compound fractures etc, the PVA is turned into a kind of foam.

Another use seems to be immobilizing yeast/microbes in waste water treatment. As it can be made into a very thin film this got me thinking, i wonder if a water proof version could be used as a Ion exchange membrane or a kind of 'salt bridge in a electrolysis cell?

You have beaten me!! Off to the shops at 8:30am to grab some more PVA .

Slime is apparently 8% Borax, i will grab what info i can find tonight. I have also seen mention of curing with heat.

Can you link to the stuff you did with your stretchO meter? Turns out to be handy Gizmondo you made there.

Percentages are a bit hard to calculate as this wood glue bottle just says 'Good for sticking any kind of wood, paper, cardboard etc. Do Not Eat' on it.

Edit:

Snappy Sugru thing :-
http://www.sciencemadness.org/talk/viewthread.php?tid=&...


[Edited on 9-9- by aga]

Hmm. Mabye Less is More after all ...



Left to right we have PVA samples A B C D
14.3g, 17.6g, 18.8g, 15.4g wood glue respectively.
(the glue 'dollops' rather than pours)

All were diluted to 100g with distilled water, then mixed thoroughly.

A borax solution was made from 10g borax decahydrate made up to 100g with water.

This was stuck in a 650W microwave for 30 seconds as the borax did not want to dissolve. After heating it dissolved completely.

Sample A had 30g of the borax solution added, stirred vigorously.

Immediately on stopping stirring a precipitate formed.

Sample B had 20g, C had 10g and D had 5g of the borax solution and all were treated in the same way with a fresh disposable stirrer.

For good measure all samples were put in the microwave for 90 seconds and mixed again, then left to settle.

After decanting off the water, the samples were dumped onto aluminium foil.

Only samples C and D exhibit any cohesivity.
A and B are more like pastes.

Conclusion:-

Mess with it some more to see if it can be cross-linked enough to make it stretchy, probably bash it a bit to get more water out.

I found PVA glue as a non brand bottle, off to town to look in builders merchants for larger amount of a branded one.

My thinking is the RSC mention 4% and 8% solutions (presumably of glue), a branded product 'might' have a MSDS so that 'might' tell me the %.

I will modify your experiment slightly, test tubes same length and same amount in each, glue unwatered first and time how long for it to exit an upturned tube.

I might also try and use a microwave to gently dry it a little, i dont have formaldehyde so cant try that yet.

Apart from that i will use same amounts as you did and also some with no water added.

I found several references to it stretched slowly, so i take it we just have to mess with amounts until we get it right .

Thanks for the 'RACK' thread, once i get something that resembles a rubber/polymer, i will know what shape to cut. I can get the rest of the stuff ready while i wait for the bus!!



Havnt tracked it down yet but looks like there is some info in the Journal of chemical education.

Journal of Chemical Education, Jan. , #63, pp. 57-60

I will see if i can find it on scihub.

Sci-Hub seems down for me, i will try again later!

Found the article reference though

10./ed063p57

[Edited on 10-9- by NEMO-Chemistry]

Found a working server, the article dosnt say much more than is already known. Out of interest if i post any papers do i do it in the thread or in references?

[Edited on 10-9- by NEMO-Chemistry]

Should have checked first!! shop shuts at lunchtime on a Saturday! I will have to grab some Monday now . Gives me a chance to look into a couple of things i want to try out .

Might not be a great result this here PVA + Borax.

This afternoon the precipitates are basically lumps of white rock, having sat out in 38+ C all day.

If the material needs the water, yet loses it, i doubt i'll be able to make any standard conditions under which to test it.

Hmm. Maybe it likes oil ...

We might manage 3.8C here but i doubt its going to go past 5C this week lol.

As always there seems to be conflicting advice on how to prepare! Got some old glue from the back of the shed, not much in it so maybe worth spending my time reading up and getting the 'slope 'O' Meter built'.



Just measure, mix and observe.

There isn't much more to it than that.

I might have got it entirely wrong. I tried with a small amount of the white PVA and didnt get anything worth while.

reading up some more it looks like i should use the clear PVA glue like the elmers stuff. I am not positive but i think they are slightly different.

Anyway apparently in acid they fall apart and in alkali they dont, i will grab some on the way home tomorrow and get cracking on it.

if i get it working we hit another problem......Turns out it is meant to be a non Newtonian fluid, so if we stretch it slowly it will stretch and stretch and stretch. But try and stretch it quickly and it breaks.

So i will give it a go, but its likely not to work out how i was hoping.

Quote: Originally posted by NEMO-Chemistry  I might have got it entirely wrong. I tried with a small amount of the white PVA and didnt get anything worth while.

reading up some more it looks like i should use the clear PVA glue like the elmers stuff. I am not positive but i think they are slightly different.

Anyway apparently in acid they fall apart and in alkali they dont, i will grab some on the way home tomorrow and get cracking on it.

if i get it working we hit another problem......Turns out it is meant to be a non Newtonian fluid, so if we stretch it slowly it will stretch and stretch and stretch. But try and stretch it quickly and it breaks.

So i will give it a go, but its likely not to work out how i was hoping.

I think the white glue is an emulsion of polyvinyl acetate while the clear glue is a solution of polyvinyl alcohol. I would expect the borax to combine with the alcohol more easily than the acetate. Does the acetate work?

Quote: Originally posted by wg48   Quote: Originally posted by NEMO-Chemistry  I might have got it entirely wrong. I tried with a small amount of the white PVA and didnt get anything worth while.

reading up some more it looks like i should use the clear PVA glue like the elmers stuff. I am not positive but i think they are slightly different.

Anyway apparently in acid they fall apart and in alkali they dont, i will grab some on the way home tomorrow and get cracking on it.

if i get it working we hit another problem......Turns out it is meant to be a non Newtonian fluid, so if we stretch it slowly it will stretch and stretch and stretch. But try and stretch it quickly and it breaks.

So i will give it a go, but its likely not to work out how i was hoping.

I think the white glue is an emulsion of polyvinyl acetate while the clear glue is a solution of polyvinyl alcohol. I would expect the borax to combine with the alcohol more easily than the acetate. Does the acetate work?

The acetate does work 'i think', i didnt have enough to fully try it but one lot got close.

I think the acetate is alot more fussy about quantity of Borax than the alcohol. I will know later when i get home, i managed to grab a bottle at the start of lunch.

The confusion came from a number of web sites that stated both the clear and the white glue were the same thing, as you point out this isnt so.......

I found alot of reference to the clear stuff coming in 4% and 8% concentrations, but i think the acetate is different.

I have no experimental experience with slime production, so cannot say how well Elmer's Glue polyvinyl acetate white glue works with borax (if at all), but the literature seems to be clear that polyvinyl alcohol clear glue is required.

It is unfortunate that PVA is used indiscriminately for both polyvinyl acetate and polyvinyl alcohol, indeed I have run across articles that deal with both, but use the acronym without explanation making it unclear what they are saying.

And although polyvinyl alcohol adhesive is a real thing (used for document conservation use for example) it is scarce on the market, acetate white glues overwhelming predominate. I think Elmer's clear school glue may be polyvinyl alcohol, but their SDS does not say what is in it - just asserting that it is 100% "Non-hazardous substance" (Love that non-hazardous substance! Use it all the time!).

You can find real polyvinyl alcohol adhesive on Amazon by searching on that phrase, and there are many vendors of polyvinyl alcohol solution and powder on eBay (mostly marketed for slime use).

Here is the Journal of Chemical Education article about slime AND one for making the alcohol from the acetate by alkaline hydrolysis.



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[Edited on 12-9- by careysub]

[Edited on 12-9- by careysub]

Quote: Originally posted by NEMO-Chemistry   Quote: Originally posted by wg48   Quote: Originally posted by NEMO-Chemistry  I might have got it entirely wrong. I tried with a small amount of the white PVA and didnt get anything worth while.

reading up some more it looks like i should use the clear PVA glue like the elmers stuff. I am not positive but i think they are slightly different.

Anyway apparently in acid they fall apart and in alkali they dont, i will grab some on the way home tomorrow and get cracking on it.

if i get it working we hit another problem......Turns out it is meant to be a non Newtonian fluid, so if we stretch it slowly it will stretch and stretch and stretch. But try and stretch it quickly and it breaks.

So i will give it a go, but its likely not to work out how i was hoping.

I think the white glue is an emulsion of polyvinyl acetate while the clear glue is a solution of polyvinyl alcohol. I would expect the borax to combine with the alcohol more easily than the acetate. Does the acetate work?

The acetate does work 'i think', i didnt have enough to fully try it but one lot got close.

I think the acetate is alot more fussy about quantity of Borax than the alcohol. I will know later when i get home, i managed to grab a bottle at the start of lunch.

The confusion came from a number of web sites that stated both the clear and the white glue were the same thing, as you point out this isnt so.......

I found alot of reference to the clear stuff coming in 4% and 8% concentrations, but i think the acetate is different.

Not the best source but wiki thinks they both work.
Apparently there are different grades of PVAl depending how much acetate is left in them. This suggests that there are also different grades of PVAc depending on the acetate content.

Perhaps borax is sufficiently alkaline to catalyze the replacement or hydrolysis of the acetate.

Of cause you can dry a sample of your PVA and weigh it before and after to determine its water content.



Thanks for that, yes some of the sites are confusing. I will get some powder and make some, i also found a paper that says you can use acetate but it dosnt seem as straightforward.

Some sites just refer to white wood glue, this i have always taken to mean the Acetate and the clear glue to be the alcohol.

Acetate does link but it isnt what i am after by a long way!! Thanks for the links. Time to go spending on ebay .

Quote: Originally posted by wg48  ...
Not the best source but wiki thinks they both work.
Apparently there are different grades of PVAl depending how much acetate is left in them. This suggests that there are also different grades of PVAc depending on the acetate content.

Perhaps borax is sufficiently alkaline to catalyze the replacement or hydrolysis of the acetate.

Of cause you can dry a sample of your PVA and weigh it before and after to determine its water content.



Yes the presence of some alcohol in a white glue might account for its "sliming", and also perhaps the borax does do some hydrolysis also.

Perhaps someone can attempt a two-step process with hydrolysis with a strong alkali, followed by cross-linking with borax?

Quote: Originally posted by careysub   Quote: Originally posted by wg48  ...
Not the best source but wiki thinks they both work.
Apparently there are different grades of PVAl depending how much acetate is left in them. This suggests that there are also different grades of PVAc depending on the acetate content.

Perhaps borax is sufficiently alkaline to catalyze the replacement or hydrolysis of the acetate.

Of cause you can dry a sample of your PVA and weigh it before and after to determine its water content.



Yes the presence of some alcohol in a white glue might account for its "sliming", and also perhaps the borax does do some hydrolysis also.

Perhaps someone can attempt a two-step process with hydrolysis with a strong alkali, followed by cross-linking with borax?

I will give it a go, I found some similar information on the glues containing different amounts of Acetates and alcohol.


Might get it working after all!

What will 'working' be ?

A rubbery thing ?

 Pages:  1  2

Experiment 2

Slime Away

Cross-Linking Poly (vinyl alcohol) with Sodium Borate

Objective: The objective of this experiment is to explore the change in physical properties of a polymer as a result of cross-linking. The result of adding more cross-linking agents to a polymer is considered and another model of cross-linking is viewed.

Applications:

There are a number of uses of the PVA polymer we are studying:

1. They may be used in sheets to make bags to act as containers for pre-measured soap you simply throw into a washing machine.
2. The PVA sheets may be made into larger bags to be used by hospitals as containers for the cotton cloth used in the operating rooms or to hold the bed linen or clothing of infected patients.

Time: This experiment will require approximately 15-20 minutes to run and clean up.

Materials and Supplies:

• 100 ml/group of poly (vinyl alcohol) 4%
• 10 ml of sodium borate 4%
• Styrofoam cups and wooden stir sticks (tongue depressors)
• Zip lock bags or latex gloves (surgical)

General Safety Guidelines:

• Laboratory aprons and goggles should be worn in this experiment as in all procedures.
• Both the borax and the PVA will burn the eyes. Hands should be washed at the end of the experiment.

Procedure:

The polyvinyl alcohol and sodium borate are mixed together in approximately a 10 to 1 ratio.

1. 100 ml of the 4% poly (vinyl alcohol) is added to a Styrofoam cup .
2. Food coloring can be added to the PVA in the cups to make different colors. Simple food coloring is recommended. This coloring should be added before any of the borax solution has been added, or it can be added directly to the borax solution.
3. Add 10 ml of the 4% cross-linker (sodium borate) to each cup. Begin stirring the mixture immediately with your wooden tongue depressor.
4. Make observations as to what is occurring as the reaction proceeds.
5. Within a couple of minutes the slime will be formed. Lift some of it out with the tongue depressor and make your observations. Record your observations on your data sheet.
6. Take some in your hand and stretch the slime slowly. Record your observations on your data sheet.
7. Repeat the stretching exercise only this time do it rapidly. Record your observations on your data sheet. Compare the results of the two tests. The slime is non toxic and is safe to handle, so you can put it in a Zip-lock bag (or latex glove) and seal it to take home.
8. Follow good laboratory procedure and wash your hands with soap and water. It is recommended that this procedure be followed whenever handling this material. Keep it in the glove or bag until it is discarded. The sodium borate or PVA could burn your eyes.
9. Place a small amount of the PVA on a paper towel and set it off to the side to dry until tomorrow. Upon returning to class the next day, record in the data section your observation of the slime.

Data and Analysis:

Observation of the PVA before the sodium borate is added:

Want more information on PVA Powder Benefits? Feel free to contact us.

Additional reading:
Key Questions to Ask When Ordering METRIC MALE Integrated Hose Fittings

Observation of the PVA after the sodium borate is added:

Observation of stretching the cross-linked PVA slowly:

Observation of stretching the cross-linked PVA rapidly:

Observation of the cross-linked PVA left out in the air overnight:

Questions:

1. What are the physical properties that change as a result of the addition of sodium borate to the poly (vinyl alcohol).
2. What would be the effect of adding more sodium borate to your cup (your thoughts only)?
3. After making the observations on the dried PVA, how does the water affect the elasticity of the polymer? What is elasticity?
4. Find and circle the repeat unit in the polymer molecule below?
   
5. What is the formula of the poly (vinyl alcohol) monomer circled above? (Your teacher may want to show you how to alter this slightly after you have drawn the structure.)

6. In the picture below, circle the borax cross-linking agent.
   

Teacher Notes:

Objective: The objective of this experiment is to explore the change in physical properties as a result of cross-linking polymers. The results of the addition of more cross-linking agents are considered and another model of cross-linking is viewed. Students also have an opportunity for monomer identification.

Experimental:

1. The Polyvinyl Alcohol as a solid is mixed in water to make a 4% solution. That is 40.0 grams of PVA per 960 grams (milliliters) of water. The best results are obtained by heating the water to about 80oC on a hot plate with magnetic stirrer. Sprinkle the PVA powder in very gently and slowly on the top of the solution while stirring so as not to cause the mixture to clump together. Temperatures above 90oC may result in decomposition of the PVA and perhaps the creation of an odor to the solution. Continue to sprinkle the PVA into the hot solution while it is stirring. After all of the PVA has been added to the water, place a top on the vessel. If the water evaporates off, a skin of PVA will form. This PVA sheet might also be a nice item to lift off and show the students. Continue stirring until the mixture is uniform (note also that it will be somewhat viscous). Allow the solution to cool, and the resulting solution will be ready for the students to use.
2. If students are adding a dye to their PVA, make sure they do this before the addition of borax.
3. The borax (sodium borate) can be obtained from your grocery store as "Twenty Mule Team Borax," a laundry bleaching agent. The borax is mixed at a 4% concentration in water. To do this measure out 4 grams of borax and dissolve in 96 grams (milliliters) of water (note: Water has a density of 1 g/mL).
4. The material becomes more viscous as we mix the PVA and the borax. It will reach a maximum level of viscosity and will not thicken further without more cross-linking agent. The addition of a higher ratio of Borax will result in a very viscous polymer (like Jell-O).

Theoretical:

The polymer used is "poly (vinyl alcohol)". The monomer has a formula of:

• Borax is sodium borate, Na3BO3. The borax actually dissolves to form boric acid, H3BO3. This boric acid-borate solution is a buffer with a pH of about 9 (basic). Boric acid will accept a hydroxide OH- from water as indicated on the next page.
  
  
  The hydrolyzed molecule will then act in a condensation reaction with PVA as indicated in the last question on the student laboratory.
  
• In the above illustration, two PVA molecules are shown being cross-linked by a hydrated borax molecule. Four molecules of water are also produced.
• The resulting material is about 95% water. It is the water that gives the polymer flexibility. Note that as the polymer dries it returns to its solid phase now as a sheet that is rigid and almost transparent.
• The PVA does not dissolve easily in water. Prepare the PVA solution at least one day in advance.
• Guar Gum dissolves in water much more easily than PVA, but seems to "jell" at a much more unpredictable rate than the PVA mixture does. For this reason, PVA is preferred.

Additional reading for more in depth information can be found in:

Journal of Chemical Education, Jan. , #63, pp. 57-60.

Sample Data and Analysis:

Observation of the PVA before the sodium borate is added:
The solution is fluid.

Observation of the PVA after the sodium borate is added:
The mixture becomes more viscous (thicker).

Observation of stretching the cross-linked PVA slowly:
The slime flows and stretches.

Observation of stretching the cross-linked PVA rapidly:
The slime breaks.

Observation of the cross-linked PVA left out in the air overnight:
It became a dry film.

Answers to Questions:

1. The mixture becomes more viscous (thicker).
2. The mixture would jell.
3. The ability of the cross-linked polymer to stretch decreases. The polymer becomes more brittle and will break.
5. C2H3OH
6. The hydrated borax, minus the four hydrogens are shown on the previous page bonding two chains of the PVA polymer together.

If you are looking for more details, kindly visit PVA in Paper Manufacturing.