Polymer characterization and gas permeability of poly(1-trimethylsilyl-1-propyne) [PTMSP], poly(1-phenyl-1-propyne) [PPP], and PTMSP/PPP blends

Abstract

Pure gas and hydrocarbon vapor transport properties of blends of two glassy, polyacetylene‐based polymers, poly(1‐trimethylsilyl‐1‐propyne) [PTMSP] and poly(1‐phenyl‐1‐propyne) [PPP], have been determined. Solid‐state CP/MAS NMR proton rotating frame relaxation times were determined in the pure polymers and the blends. NMR studies show that PTMSP and PPP form strongly phase‐separated blends. The permeabilities of the pure polymers and each blend were determined with hydrogen, nitrogen, oxygen, carbon dioxide, and n‐butane. PTMSP exhibits unusual gas and vapor transport properties which result from its extremely high free volume. PTMSP is more permeable to large organic vapors, such as n‐butane, than to small, permanent gases, such as hydrogen. PPP exhibits gas permeation characteristics of conventional low free volume glassy polymers; PPP is more permeable to hydrogen than to n‐butane. In PTMSP/PPP blends, both n‐butane permeability and n‐butane/hydrogen selectivity increase as the PTMSP content of the blends increases. © 1996 John Wiley & Sons, Inc.

Physical aging in carbon molecular sieve membranes

“…Based on the above discussion, as with glassy polymers, the starting materials and the processing conditions used to [27,31,34,61,62]. CMS membranes prepared from Matrimid â , 6FDA-DAM, and 6FDA/BPDA-DAM 550°C/2 h and UHP argon pyrolysis were investigated for time dependence.…”

Structure-gas Transport Property Relationship of Hyperbranched Polyimide-silica Hybrid Membranes

“…(1) dt dp RT V p L A 22414 P = where A is the membrane area (cm 2 ), L is the membrane thickness (cm), p is the upstream pressure (cmHg), V is the downstream volume (cm 3 ), R is the universal gas constant (6236.56 cm 3 cmHg/mol K), T is the absolute temperature (K), and dp/dt is the permeation rate (cmHg/s). The gas permeability coefficient can be explained on the basis of the solution-diffusion mechanism, which is represented by the equation [21,22] : …”

A Novel Poly(4‐methyl‐2‐pentyne)/TiO2 Hybrid Nanocomposite Membrane for Natural Gas Conditioning: Butane/Methane Separation

“…[1][2][3][4][5][6][7][8] After the 1980s, among the polymeric membranes (membranes with rubbery selective layer) for use for the separation of hydrocarbon mixtures, as well as the removal of organic components from permanent gas streams, great attention was afforded to the disubstituted polyacetylenes, which are glassy polymers that have the highest known gas permeability. [7][8][9][10][11][12][13][14][15][16][17][18] Polyacetylenes such as poly(4-methyl-2-pentyne) (PMP), [7,8,16] poly(1-trimethylsilyl-1-propyne) (PTMSP), [12,13,15] and poly(1-trimethylgermyl-1-propyne) (PTMGP) [17,18] are more permeable for large organic molecules (condensable gases) than for permanent gases. This property has been attributed to an extremely high fractional free volume that results from an unusually loose packing of stiff polymer chains that contain carbon-carbon double bonds and bulky side-chain groups.…”