A technique is described for the preparation of arborescent copolymers containing poly(2-vinylpyridine) (P2VP) segments. 2-Vinylpyridine is first polymerized with 1,1-diphenyl-2-methylpentyl-lithium in tetrahydrofuran in the presence of N,N,N',N-tetramethylethylenediamine (TMEDA). The graft copolymers are obtained by titration of the P2VP anions with a solution of a chloromethylated polystyrene substrate. Copolymers incorporating either short (M-w approximate to 5000) or long (M-w approximate to 30 000) P2VP side chains were prepared by grafting onto linear, comb-branched (G0), G1, and G2 chloromethylated arborescent polystyrenes. Branching functionalities ranging from 14 to 3880 and molecular weights ranging from 8.2 x 10(4) to 6.7 x 10(7) were obtained for the copolymers, while maintaining a low apparent polydispersity (M-w/M-n approximate to 1.06-1.15) after grafting. Characterization data for these materials from size exclusion chromatography and light scattering indicate that they have a highly compact structure. Dynamic light scattering results show that the arborescent poly(2-vinylpyridine) copolymers expand much more in solution than the linear homologous polymers when protonated with HCl. This is attributed to the higher charge density attained in the branched copolymers.