Divinylbenzene living anionic polymer reaction

Hyperbranched polymers have also been prepared via living anionic polymerization. The reaction of poly(4-methylstyrene)-fo-polystyrene lithium with a small amount of divinylbenzene, afforded a star-block copolymer with 4-methylstyrene units in the periphery [200]. The methyl groups were subsequently metalated with s-butyllithium/tetramethylethylenediamine. The produced anions initiated the polymerization of a-methylstyrene (Scheme 109). From the radius of gyration to hydrodynamic radius ratio (0.96-1.1) it was concluded that the second generation polymers behaved like soft spheres. 

The PS network was synthetized by the end-linking procedure using the anionic block copolymerization of a mixture of linear PS (H) chains, containing 5% of perdeuterated chains of the same molecular weight, with divinylbenzene (three molecules per living end). The crosslinking reaction was performed in the presence of an aprotic solvent (equal volume of tetrahydrofuran and toluene), the overall polymer volume fraction being equal to 0.1. 

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