POLYMER CHARACTERIZATION AND GAS-PERMEABILITY OF POLY(1-TRIMETHYLSILYL-1-PROPYNE) [PTMSP], POLY(1-PHENYL-1-PROPYNE) [PPP], AND PTMSP PPP BLENDS/

Pure gas and hydrocarbon vapor transport properties of blends of two g lassy, polyacetylene-based polymers, poly(1-trimethylsilyl-1-propyne) [PTMSP] and poly(1-phenyl-1-propyne) [PPP], have been determined. Soli d-state CP/MAS NMR proton rotating frame relaxation times were determi ned in the pure polymers and the blends. NMR studies show that PTMSP a nd 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 v olume. PTMSP is more permeable to large organic vapors, such as n-buta ne, than to small, permanent gases, such as hydrogen. PPP exhibits gas permeation characteristics of conventional low free volume glassy pol ymers; PPP is more permeable to hydrogen than to n-butane. In PTMSP/PP P blends, both n-butane permeability and n-butane/hydrogen selectivity increase as the PTMSP content of the blends increases. (C) 1996 John Wiley & Sons, Inc.