Dear Narayanan Subramanian, controlled polymerization techniques are well suited for this purposes, i.e., defined MW and narrow polydispersity close to 1. Which polymerization process is used for the synthesis of this polyether, polyaddition or step growth polymerizations. My Regards

the stoichiometric ratio of the bifunctional monomer or the monofunctional monomer must be adjusted to control the Mw. If the ratio is too large the Mw will be lower than expected, it should be evaluated. About polydispersibility index It is necessary to decrease the degree of polymerization or by removing low molecular weight and high molecular weight fractions,

If you have any doubts you can contact me,

Regards.

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check this : https://www.sciencedirect.com/topics/engineering/polydispersity-index

Thank you all. What is the significance of number average and weight average molecular weight. What information we get?

Dear Narayanan Subramanian, no thanks. The attached file gives definitions of the different entities related to polymer MWs. My Regards

We generally use living polymerization to decrease PDI. We use RAFT technique. use dialysis to remove low molecular weight fraction and then we get Mn from NMR and then we do GPC

Thank you Juthi Pal Pal. Could you explain some more about living polymerization (How to do). Also what is RAFT technique. Any reference related to decreases PDI.

RAFT is reversible addition fragmentation charge transfer polymerization. It is a living polymerization technique so usually PDI comes at low range. And also it is a controlled polymerization.You need an initiator ( e. g. AIBN) a RAFT agent and monomers. It is a widely used technique, many material will be available if you search on internet. Depending on your monomers the RAFT agents will varry.