Blending PPO-based molecules with Pebax MH 1657 in membranes for gas separation

© 2018 Wiley Periodicals, Inc. This work explores the possibilities to blend block copolymers, i.e., Pebax MH 1657, with a variety of cheap poly(propylene oxide)-rich molecules which could potentially play a double role in the resulting membranes as dispersing/stabilizing agents in multi-component casting solutions and as a gas transport medium in the final membrane. These membranes were prepared by solution casting and were characterized by differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, X-ray diffraction, density measurements, and Fourier transform infrared-attenuated total reflection, while additive incorporation was also studied with theoretical calculations. Gas permeation measurements showed that this approach resulted in increased permeabilities at the expense of mixed-gas selectivity. An interpretation of the blend structure was finally made using gas transport models. The compatibility of these additives with the synthesis of selective gas separation membranes may enable a potential double role in membrane synthesis, i.e., as stabilizing agents in membrane synthesis and as a gas transport medium in the final membrane. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46433.