Chemical Forums

Specialty Chemistry Forums => Chemical Engineering Forum => Topic started by: spankytank on December 12, 2021, 04:39:07 AM

Title: What to consider when changing solvent in polymerization reaction
Post by: spankytank on December 12, 2021, 04:39:07 AM
Hi,
I have an upcoming presentation to hold and the issue is as following ;

"The company is going to launch a new product (Green Polymer) in 8 months’ time. The Green Polymer will be based on an existing polymer product (NotSoGreen Polymer) and manufacturing process, where the solvent used in the reaction and work-up must be replaced. The existing process is running at 85 °C in a 10 L batch reactor for 12 h.
The manufacturing scale for the new product will remain at 10 L, only solvent (no other reactants) will be replaced.
Stakeholder wants the Green polymer product to meet specifications of the existing NotSoGreen polymer product.
You are part of a cross functional project team and the core team lead wants you to help creating an experimental plan.
Describe (feel free to make assumptions where they may be necessary):
1. What kind of experiments do you believe are relevant?
2. What do you think are the most critical challenges you would encounter and how would you solve them?
"

My initial thoughts is that solubility is very important, that I test whether the "green solvents" can solubilize the starting material, aswell as the intermediate- and finished product. As this reaction is at 85 °C for 12 h it is likely to be polycondensation, so we might not want to use for example ethanol as it might react with the monomers (if it is a polyester reaction etc). Polymerization is also heavily affected by kinetics by that different solvents might lead to a slower/faster reaction rate, and that should be investigated. The solvent should also be able to manage 85 °C (if not found necccessary to change the temperature).
Are there other big issues I should look into?

I appreciate all input, thanks. 
Title: Re: What to consider when changing solvent in polymerization reaction
Post by: wildfyr on December 12, 2021, 06:44:28 AM
Decent analysis. I might also ask, how does the new solvent affect the purification, and are either new or old solvents distilled and reused? Might also wonder about safety like flammability and toxicity. What impurities or inhibitors are in new solvent?

Also, 85c 12 hrs not a typical polycondensation. 110 C or so would be, because most condensations are toluene water azeotrope under dean stark conditions to make polyesters. 85C could be many things, including some more atypical polycondrnsations.