Аннотация:Favorable conditions were selected for the graft polymerization of styrene and oligo(dimethylsiloxane) on an ethylene-acetylene copolymer containing extended systems of conjugated double bonds, Microphase composition of the graft copolymers was studied by X-ray diffraction and differential scanning calorimetry, It was found that polymers containing above 30 mol % of grafted component exhibit a minimum mutual influence of the two blocks. The grafting does not lead to any significant amorphization of the mixed amorphous-crystalline structure of the initial copolymer.