A linear, nearly monodispersed poly(4-vinylpyridine)-b-polybutadiene-b-poly(4-vinylpyridine) (VBV) has been synthesized using a dicarbanion initiator. The diinitiator, comprising a 2:1 molar ratio of t-butyllithium to m-diisopropenylbenzene, was prepared at -20 degrees C in the presence of triethylamine, amounting to 1.5 times of the t-butyllithium moles to ensure a difunctionality. The VBV synthesis was conducted at -80 degrees C in a mixed THF/toluene solvent in order to circumvent the chain branching reactions arising from the -N=CH- group of the 4-vinylpyridine. The absence of chain branching under such conditions has been verified by GPC/MALL and UV analyses, and syntheses at higher temperatures are detrimental. Compared with an analogous polystyrene-b-polybutadiene-b-polystyrene (SBS), VBV relaxes slower with a higher activation energy of relaxation. Although phase separation occurs for both VBV and SBS, VBV exhibits a different morphology having a hard domain of a droplet-cluster type. The polarity of the poly(4-vinylpyridine) not only produces a T-g higher than that of the polystyrene, but also increases the T-g of the rubbery polybutadiene phase. The relaxation mechanism deduced based on the X-method indicates that contributions to relaxation for both VBV and SBS are in such order: physical flow > domain destruction > physical untanglement.