Highly Gas Permeable Polyamides Based on Substituted Triphenylamine

Abstract

We present synthesis, characterization, and gas transport properties of a series of new aromatic polyamides (PAs) containing tri-tert-butylphenol-substituted triphenylamine moiety (TPA). The PAs showed a good combination of thermal and mechanical properties (Tg up to 284 °C, Td10 up to 400 and 460 °C in air and nitrogen, respectively, and tensile strength up to 68 MPa). Gas transport properties of these membranes were investigated for different gases at 35 °C. The PAs showed high gas permeability with moderate gas selectivity [PCO2 = 119.0, PO2 = 29.0 barrer and PCO2/PCH4 = 37.19, PO2/PN2 = 9.67]. The effect of the substituted TPA unit on the gas transport properties of these membranes has been investigated and analyzed using molecular dynamics simulations. A thorough structure/property relationship for this class of materials has been established that may serve as a guide to future design of PA-based gas separation membranes.