Synthesis and Gas-Transport Properties of Poly(1-trimethylsilyl-1-propyne)- and Poly(4-methyl-2-pentyne)-Based Chlorinated Polyacetylenes for Membrane Separation of Carbon Dioxide

Abstract

This work is devoted to the chemical modification of the polymers of 1,2-disubstituted acetylenes for the creation of gas-separation membranes possessing enhanced stability to aliphatic hydrocarbons and CO₂ selectivity. The feasibility of obtaining polyacetylenes containing chlorine atoms in the side substituents of poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(4-methyl-2-pentyne) (PMP) by radical chlorination with N-chlorosuccinimide has been shown. The reaction has been carried out under mild conditions to minimize the possibility of polymer degradation and other side reactions. The obtained polymers exhibit good mechanical and film-forming properties as well as high thermal stability. Chlorinated PTMSP possesses enhanced stability to alicyclic and aliphatic C₅–C₁₂ hydrocarbons. It has been shown that in the case of introduction of chlorine into the structure of PTMSP and PMP, the CO₂/N₂ and CO₂/CH₄ selectivities increase, with the high level of permeability being retained.