Abstract
Two methods for monitoring the physical aging of polymer membranes by gas permeability measurements are compared. The traditional method with intermittent permeability monitoring is compared to the continuous permeability monitoring when the membrane occurs under excess pressure of the permeating gas throughout the experiment. A composite membrane with a thin (1 mu m) selective polytrimethylsilylpropyne layer containing 10 wt % organic nanoparticles (porous aromatic frameworks) was taken as an example. The continuous permeability monitoring allows acceleration of the physical aging of the membrane and considerable (by two orders of magnitude) reduction of the experiment time. Fast physical aging in a carbon dioxide stream can be an efficient way to reach equilibrium gas permeability of membranes based on glassy polymers with high void volume.