Effect of introduction of cardo cyclohexylidene moiety on gas transport properties of fluorinated poly(arylene ether)s

This article describes the synthesis, characterization and gas transport properties of a series of new fluorinated poly(arylene ether)s (PAE)s, prepared from 4,4′-cyclohexylidenebisphenol on reaction with five structurally different aromatic bisfluoro monomers. The PAEs were characterized by elemental analyses, NMR, FTIR, GPC and thermal techniques. The polymers showed high Tg (up to 231 °C), outstanding thermal stability (up to 516 and 495 °C in nitrogen and air respectively), high tensile strength (up to 73 MPa) and low dielectric constant (∊ = 2.31). Gas transport properties of these PAE membranes were investigated at three different temperatures using the four different gases (e.g., CH4, N2, O2 and CO2). The effect of cardo cyclohexylidene unit in the PAE membranes on gas transport properties has been investigated. The PAEs in this investigation showed high gas selectivity [α(CO2/CH4) = 44.85] and comparable permeability with many other previously reported poly(arylene ether)s.