High molecular weight polymers star structures

Using this method asymmetric stars of the type (PSa) (PSb)/7 were prepared.77 Living PS chains were obtained by s-BuLi initiation and reacted with a small amount of DVB to give a living star polymer. The anionic sites of the star core were subsequently used to initiate the polymerization of a new quantity of styrene. This initiation step was accelerated by the addition of a small quantity of THF. It was revealed by SEC analysis that high molecular weight species were also present, probably due to the formation of linked stars. These structures can be obtained when living anionic branches of one star react with the residual double bonds of the DVB-linked core of another star. 

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