Poly(etherimide)s: correlation of positron annihilation lifetime studies with polymer structure and gas permeability

This paper describes the results of positron annihilation lifetime measurem ents on a series of poly(ether imide)s for which permeabilities and permsel ectivities for gas separation have been determined previously. Positron lif etimes and intensities vary systematically with changes in polymer structur e and correlate with the permeabilities in separation of carbon dioxide and methane. Some apparent scatter in the data might, in part, be associated w ith differences in the interactions of ortho-positronium with molecular cav ities as polymer structures are varied. (C) 1999 Published by Elsevier Scie nce Ltd. All rights reserved.