vinylversatate emulsion

[manelchem]

we have a problem with the production of the vinyl versatate emulsion ( latex for paint) during the second stage (propagation) too much reflux happens, we loose exothermic reaction, we can't understand the cause of the problem.
i need some helps.

 

[Latexman]

i need some helps.

That, is an understatement.

I recommend you study the Posting Guidelines (to the right of "Reply To This Thread"). Concentrate on "Tips on how to write a 'good' question". If English is not your mother tongue, and this is causing a problem being understood, re-double your efforts.

I have dozens of questions rolling around in my mind whose answers would help me figure out the problem, but I'm not going to ask them . . . not yet.

Give it another shot manelchem. This time, include as many details as you can (P&ID, recipe, temps., pressures, flows, etc.) For example, I doubt this is a vinyl versatate homopolymer, right?

Good luck,
Latexman

 

[manelchem]

This is my first participation in a forum and I wasn't sure that someone will be interested in my problematic, English is not my native tongue also.
For this I would thank you for your interesting and I will explain more my problematic.
we are producing a latex based on vam/veova/Acrylic acid, we used to do the same recipe in the main rector with out any problem but last two week the production wasn't OK, we had a lot of reflux which decreases temperature of the reaction ( from 82-81 to 76°C), we couldn't control the reflux so the end product was rich of free monomers and with very low viscosity (200cP instead of 1500cP) and a low solid content ( 46% instead of 50%).
We did the same recipe in the pilot plant with exactly the same raw materials, the result was OK , reaction worked well, and we didn't see any reflux.
We have inspected the reactor and have seen any problem so.

 

[Latexman]

Is it using a thermal initiator, like a persulfate? What is the temperature of the reflux? I bet it's < 65 C.

Good luck,
Latexman

 

[Latexman]

Did you find and fix the problem?

Good luck,
Latexman

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