RAFT Polymerization - Reaction Setup 

Thank you for your nice comment! I don't really have any experience in this area. One example is PEGylation (adding polyethylene glycol to a protein) can help improve stability/retention in the body. The following article from Sigma Aldrich appears to go over some of the different synthetic approaches: www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/drug-delivery/protein-and-peptide-polymer-conjugates

Thank you for the nice comments. 1. I typically run my RAFT polymerizations under nitrogen. I know polymerizations can be performed under vacuum (common for anionic polymerizations). I’m not sure if a rubber septum would hold vacuum well enough to prevent air from getting the flask after a few hours. 2. We use oil baths in my lab to heat reactions. Specifically I used the oil bath because I used AIBN a thermal radical initiator, which has to be heated to ~65-80 degrees Celsius to produce sufficient radicals for polymerization to occur. A different type of radical initiator could be used to perform the reaction at ambient conditions.

1. When polymerizing under vacuum, it is difficult to take samples. It will be more difficult to obtain the desired monomer conversion, therefore, it is possible to make a mistake and get the wrong molecular weight of the polymer.

I made them in anisole, because I’d normally use it as a solvent for my polymerizations. Anisole is also high boiling so if stored cold the concentration won’t change much. Should be stable especially the CTA. if you have a reliable balance and doing reactions at large enough scale you could measure the CTA and AIBN directly.

Thank you. With RAFT you will typically calculate the DP of your polymer by multiplying monomer conversion by your M:CTA ratio. So if I used a 100:1 ratio and stopped at 50% conversion, the calculated DP would be 50. For the CTA:AIBN ratio 10:1 is commonly used. You want to use a relatively small amount of initiator that way most polymer chains are initiated by your CTA, retain living character, and to limit termination. As for solvent it depends on the polymerization, I've used 1:1 to 1:2 (M:S) but I have done some reactions without solvent as well. My advice would be to find a paper/patent that uses your monomer or similar one as a basis. If you have access to reaxys or scifinder they can be helpful tools for finding procedures pubs.acs.org/doi/10.1021/acs.macromol.1c02662 Page 4 in the supporting information has a detailed experimental procedure. pubs.acs.org/doi/10.1021/acs.macromol.7b00767 This is a good general reference about RAFT polymerization

@@MK-Chem Thank you very much for taking the time to reply to me." Does "M" mean monomer in both cases? Or is the second M derived from the mass of the reactant? Thank you very much for showing me the references. The first supporting info, which I see as your paper, is detailed and very helpful. I would like to use it with this video. Thank you.

So yes I meant M to stand for monomer in both cases. For M:CTA that is a molar ratio, so as an example 100 monomers per one CTA molecule. For the monomer:solvent ratio I meant mass ratio so for 1:1 I mean 3g of monomer and 3g of solvent. You're welcome, I'm glad you found them useful. Best of luck!

I have a little bit of experience with acrylamides; I work mostly with acrylates/methacrylates.

I quenched the reaction by cooling in an ice bath and opening to air. In this case I purified the polymer by precipitating it in a poor solvent a few times. When I have more time I hope to make additional videos covering the work up and characterization.

@@MK-Chem hello I am also working on polymers And I am from India

In this example I used a trithiocarbonate. Similar to CAS# 870196-80-8