Semifluorinated, organo-soluble new aromatic poly(ether amide)s: Synthesis, characterization and gas transport properties

A series of processable fluorinated poly(ether amide)s (PAs) were synthesized from a new diamine monomer, 1,4-bis-[{2′-trifluromethyl 4′-(4″-aminophenyl)phenoxy}] phenyl with four different aromatic dicarboxylic acids. The polymers have been well characterized by GPC, FTIR, NMR, XRD and thermal techniques. The PAs showed excellent thermal stability (411–468 °C for 10% weight loss), high glass transition temperatures (243–290 °C), high tensile strengths up to 83.9 MPa and elongation at break up to 21%. PA ‘6a’ showed highest permeability in barrer for image, image, image, image. PA ‘6b’ showed highest permselectivities for CO2 and CH4 (image) as well as for O2 and N2 gas pairs (image) among the series. It has been attempted to draw a structure–property correlationship between the chemical structures of the polymers and their gas transport properties on the basis of their FFV, glass transition temperatures, and chain packing density.