%0 journal article
%@ 0024-9297
%A Yave, W., Peinemann, K.-V., Shishatskiy, S., Khotimskiy, V., Chirkova, M., Matson, S., Litvinova, E., Lecerf, N.

%D 2007
%J Macromolecules
%N 25
%P 8991-8998 
%R doi:10.1021/ma0714518
%T Synthesis, Characterization, and Membrane Properties of Poly(1-trimethylgermyl-1-propyne) and Its Nanocomposite with TiO2
%U https://doi.org/10.1021/ma0714518
25 
%X The relationship between poly(1-trimethylgermyl-1-propyne) (PTMGP) microstructure and gas permeability property is reported. Controlling the synthesis conditions via TaCl5 and NbCl5 catalyst systems, tailor-made polyacetylenes in a wide range of cis/trans ratio (trans content from 35 to ~100%) were obtained. According to the cis and trans ratio in the polymeric chain, a two-phase structure was found characterized by the presence of regions with enhanced level of macrochains ordering and with amorphous regions. The polymer microstructure has been related with free-volume, gas permeability, and polymer resistance toward liquid hydrocarbons. PTMGP membranes with high trans content (80-90%) exhibited higher gas permeability than samples with low trans content. Gas permeability of PTMGP membranes decreased with the density of polymer films, i.e., with the free-volume fraction in polymers with different microstructures. Furthermore, it was demonstrated that gas permeability and resistance toward solvents of the PTMGPs are directly defined by their cis/trans microstructure and supramolecular ordering. PTMGP with well-defined microstructure (trans content between 80 and 90%) can be considered as potential membrane material for gas separation, e.g., separation of higher hydrocarbons from natural gas. PTMGP/TiO2 nanocomposite membranes were also studied for exploring the gas permeability properties and stability of polyacetylene membranes. Gas transport properties were affected slightly by TiO2 presence; however, the long-term stability was enhanced.