How can I make an AB2 hyperbranched polymers without formation of crosslinking materials by using polycondensation polymerisation method?
The formation of the gel phase is most likely due to the formation of high-MW dendrimeric macromolecules with the increasing yield (or extent of reaction).
This issue can be resolved either by "freezing" the reaction at a relatively low yield or altering its conditions to produce polymers with lower molecular weight. Another approach is to use a reaction medium that is capable of dissolving these hyperbranched polymers, however, this might necessitate the use of aggressive solvents.
It depends to your functional groups. what kind of polymer you want to synthesize?
many faktors affected this process, like solvents, concentration, functional group reactivity and temperatures. each of these should be controled
As per conventional thinking more than two functionality leads to gelation. However, this is not the case as Flory predicted. The controlling factor towards soluble product are the extent of reaction (concentration), reactivity, temperaturer etc. You may find report on extensive study regarding this.
Had some success by reducing concentration and/or solvent change, as mentioned above. Protecting groups may also be effective but a little more involved.
Many thanks for your advice John George Hardy , I will try my best to do it.
One i reduced the temperature of the reaction but i got a very low molecular weight !
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