<p>A series of polymers containing diacetylene-containing polyethersulfone by oxidative coupling polymerization of dipropargyloxydiphenylsulfone (BPS) and dipropargyloxy bisphenol-A (BPA) monomers were synthesized; the reaction was carried out under mild conditions and afforded high yields. Using these copolymers, films were made to determine the permeability for the following gases: CO₂, CH₄, N₂, O₂. The copolymers were amorphous and soluble in organic solvents except that the homopolymer from bis(4-propargyloxy)diphenyl sulfone was a crystalline polymer insoluble in most organic solvents. Films of copolymers were cast from solutions of each copolymer in chloroform at room temperature. The amorphous copolymer films slowly underwent cross-linking reactions in solid state during storage given a stronger mechanical force to copolymer. The relationship between cross-linking and mechanical properties was also studied. The incorporation of the diacetylene groups in the chain backbone of copolymer caused less permeability with a factor of ten times in its comparison with the polysulfones based on bisphenol-A synthesized by nucleophilic condensation, on the other hand. Moreover, the combined ease of processing and resultant stability was highlighted.</p>