I had done acrylic acid based polymer to use it as a dispersing agent in our product range. I had used a process with fast addition of initiator (APS) for polymerisation and get higher molecular weight. Please, are there any process controls required to bring down the molecular weight of the polymer?
Can you name any information concerning the weight range or your procedure itself? Increasing the temperature may be one way to reduce the size of the polymer (e.g. for anionic polymerisation). Monomer / initiator ratio is also a parameter or the stabilization of the emulsion or of the final particle (as shown in the article).
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Dear Mr. Michael, Thank you very much for your inputs. It is of great help for me. I don't know the average molecular weight. But, I had made 30 % solution of acrylic acid polymer with APS as initiator. Initially, I get a viscosity of 15000 cps which may be of very high average molecular weight and it is successfully reduced to 6000 cps by increasing the polymerization temperature from 70 C to 90 C. Now i am trying for various other process controls for reducing the viscosity further, My target to achieve 2000- 3000 cps which is ideal for further processing in our products. Kindly let me know the procedure by which I can derive the average molecular weight of the polymer.
You can increase the concentration of initiator as DP is inversely proportional to (Initiator conc)^1/2. You can reduce the monomer concentration as well as D.P. is directly proportional to monomer concentration.
You can increase the concentration of initiator as DP is inversely proportional to (Initiator conc)^1/2. You can reduce the monomer concentration as well as D.P. is directly proportional to monomer concentration.
You can increase the concentration of initiator as DP is inversely proportional to (Initiator conc)^1/2. You can reduce the monomer concentration as well as D.P. is directly proportional to monomer concentration.
It's really a pleasure to get reply from doctorate in Institute of Chemical Technology, Mumbai. Thanks for your valuable input, Dr. Asit Baran Samui. I am trying with more amount of initiator in process to reduce the viscosity of the product. Hope it will achieve my targeted viscosity by this way. Kindly, it will be of great help. If you share some testing method for the determination of molecular weight of Polymer.
GPC is the widely accepted method. You can also try membrane osmometry or light scattering. In industrial scale viscosity average molecular weight can be used. If other methods and constants are not available use simply the inherent or intrinsic viscosity for comparison.
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