Poly(1-trimethylsilyl-1-propyne)-block-poly(4-methyl-2-pentyne) (PTMSP-b-PMP) block Copolymers of different composition were synthesized through sequential living polymerization by catalytic systems based on niobium pentachloride with organometallic cocatalysts in cyclohexane. Mechanical thermal, and gas transport properties of synthesized block copolymers are investigated The morphology of PTMSP-b-PMP can be described as a two-phase supramolecular structure which includes regions with an increased level of ordering, distributed in an amorphous phase. The observed structure of block copolymers is explained by the presence of densely packed poly(4-methyl-2-pentyne) (PMP) blocks and less ordered poly(1-trimethylsilyl-1-propyne) (PTMSP) blocks. The correlation of morphology of block copolymers with gas transport parameters as well as with resistance toward organic solvents is discussed. As result of this study, novel Polymeric Materials based on PTMSP and PMP combining resistance toward aromatic and aliphatic hydrocarbons with high gas transport parameters are synthesized.