Vinyl acetate ethylene reactions and solubility

[killswitchengage]

Hi
I am no chemical engineer in fact i am a geotechnical one but for the sake of my PhD i need your help. Idk if my question is well placed here but i wanna know what is the solubility of liquid VAE ( vinyl acetate ethylene ) in water before it hardens and does it ever react with sulfates like CaSo4 or NaSo4 as well as NaCl ? if so under which temperature ?

 

[Latexman]

It's going to depend on the MW of the VAE. Low MW will be more soluble than high MW. VA's solubility in water is 2.0 weight % at 20 C. Ethylene is not very soluble in water; it likes being a gas. One would guess low MW VAE solubility would be << 2%. But, are you talking about a temperature change of the polymer? Hot VAE liquid cooled by water where the polymer solidifies?

I don't know about the reactions you asked about.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[killswitchengage]

thanks but i don't know what MW means , i just want to know for ex NaCl at 20 C° solubility is 27 g/l so what about VAE liquid solubility in water
I am looking forward into using VAE as a binder in soils, this technique has been used very recently where VAE is dilluted in water at ratios of VAE/Water of 1/10 and 1/20. if these soils contain appreciable amounts of sulfates or chlorides what are the possible reactions that may happen ?

 

[Latexman]

MW = Molecular Weight.

The solubility of a VAE polymer in water is essentially 0 g/l.

But, you can make a stable VAE latex (VAE polymer, water, and surfactant) that is 50-70 weight % polymer, 49-29 % water and 1 % surfactant). I bet you are thinking of a latex.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[killswitchengage]

never mind now i am getting the grip of it , so latexes or inaccurately emulsions are water soluble polymers ?

 

[Latexman]

Notice the edits in my previous post.

Latex

Emulsion

A VAE latex is made by polymerizing an emulsion of vinyl acetate, water, and surfactant, i.e. emulsion polymerization.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[killswitchengage]

Thanks latexman so basically monomers are fed to the reactor under powder form and in order to polymerize them into liquid form water and surfactant is added ?
why not use the polymer under powder form rather than liquid emulsion

 

[Latexman]

More like . . . monomers are fed to the reactor in liquid form (vinyl acetate) and gas form (ethylene) where they are mixed with an initial charge of water and surfactant in order to polymerize a latex of finely divided VAE polymer particles, water, and surfactant.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[georgeverghese]

Re your query on the effect of NaCl and sulfates on this EVA copolymer emulsion, maybe this link helps ?

https://www.google.com.au/patents/US3394097

 

[killswitchengage]

ok latexman but was is the practical advantage of making emulsions rather than sticking with powders ?
@georgeverghese thanks alot it seems that sulfates are a building block for VAE latex , they also mention that sodium ions can help increase mechanical stability of this VAE dispersion , can you guys clarify what is mechanical stability ?

 

[Latexman]

I don't know of a technology that uses vinyl acetate and ethylene and directly produces powdered VAE. I think everyone uses emulsion polymerization and then spray dries the latex to powder.

Mechanical stability is the ability to flow or shear the VAE latex and it remain in it's original form. No coagulation. No formation of filterable solids. Etc. It is "stable".

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[killswitchengage]

i deeply appreciate your help thank you , i may need more answers in the futur