Gas transport properties of a series of cardo polyarylethers

Gas transport of H-2, CO2, O-2, N-2, and CH4 in a series of cardo polyaryle thers were examined over a temperature range of 30 similar to 100 degreesC. These polymers include three poly(aryletherketone)s, two poly(arylethersul fone)s, and one poly(aryletherketoneketone). It was found that the large le ngth/diameter ratio of the polymer repeat unit for cardo polyaryletherketon eketone (PEKK-C) and strong intermolecular interaction in hydrogen-bonded p olyarylethersulfone (PES-H) and hydrogen-bonded polyaryletherketone (PEK-H) resulted in a considerable increase in gas permselectivity. Alkyl-substitu ted polyaryletherketone (PEK-A), bearing a pendant bulky propyl group on th e cardo ring, simultaneously exhibited 62.5% higher H-2 permeability and 59 .8% higher H-2/N-2 permselectivity than unmodified poly(aryletherketone) (P EK-C). The causes of the trend were interpreted in terms of chain packing d ensity, segmental motion ability, steric factor, and intermolecular interac tion of polymers, together with gas kinetic diameter and critical temperatu re data. (C) 2002 John Wiley & Sons, Inc. J Appl Polym Sci 83: 791-801, 200 2.