Characterization of gas separation properties of novel polymer membranes

Polymers with high permeability (throughput), selectivity (separation efficiency), and long term stability are desired for gas separation applications. This dissertation investigates gas transport properties of two relatively novel polymer membranes: thermally rearranged (TR) polymers and UV-crosslinked poly(arylene ether ketone)s (PAEKs). TR polymers belong to a relatively recent class of materials that, due in part to high free volume and a favorable free volume distribution, have interesting gas separation performance. This work examines the structure-property relationship of several TR isomers, explores the gas transport and mechanical properties of a series of TR copolymers, and investigates the influence of toluene, a model aromatic contaminant in natural gas on pure- and mixed-gas permeation properties of TR polymers. In addition to TR polymers, this thesis also presents the influence of UV irradiation and physical aging on O2 and N2 permeation properties of ultra-thin (~150 nm thick) PAEK films. Gas permeability decreased and selectivity increased with UV irradiation and aging time. Samples irradiated in air have lower permeability coefficients and higher selectivities than samples irradiated in N2. Additionally, physical aging behavior was also influenced by the aging environment and the irradiation wavelength.