Аннотация:Linear and non-linear copolymers of the PB-b-PI sequence [PB: polybutadiene of high 1,4-microstructure (~ 92%) and PI:polyisoprene of high 3,4-microstructure (~ 55-60%)] and their corresponding miktoarm star copolymers of the PB(PI3,4)2 andPB(PI3,4)3 type were synthesized by combining anionic polymerization and chlorosilane chemistry. Molecular characteristics,thermal properties and structure/properties relationship are reported for the specific copolymers and especially the selfassembly is of major importance and interest due to the nature of the blocks. The identical electron densities between thetwo polydienes led to impossible morphological characterization through small angle X-ray scattering (SAXS) and onlytransmission electron microscopy results verify the adopted morphology for each copolymer, justifying the assumption thatthe segment-segment interaction parameter between the two polydienes of high 1,4-microstructure (~ 92%) for the PB and~ 55-60% 3,4-microstructure for the PI is well above zero. The consistency of the bulk morphology results of this studycompared with those of the extensively studied system of the PS(PI)n=1,2,3 type (PS: polystyrene), were unexpectedlycoherent. High chain flexibility provided by the two polydiene segments, leads to promising properties unattainable fromcorresponding thermoplastic triblock copolymers of these polydienes with polystyrene or PS (PS-b-PI-b-PS, PS-b-PB-b-PS),especially for rheological studies.