We describe the synthesis and the characterization of amphiphilic triarm star block copolymers based on polystyrene, poly(methyl methacrylate), poly(epsilon caprolactone), poly(L lactide) and poly(ethylene oxide) blocks.This synthesis has been achieved by a new route consisting in 2 successive initiation steps on a core molecule (a 1,1 diphenyl ethylene derivative bearing a protected hydroxy function) located at the end of a first block.Some results on adsorption onto TiO2 and micellization studies are given. Preliminary results on solid state indicate an increase of the miscibility of the different incompatible blocks.