Sou Miyata

Synthesis and gas transport properties of UV-cured low-viscosity fluorine-containing telechelic polyimide membranes

Abstract A novel ultraviolet (UV) cross-linking method using fluorine-containing telechelic polyimide membranes was investigated. The base fluorine-containing polyimide was synthesized by polycondensation using the monomers, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,3,5,6-tetramethyl-1,4-phenylene diamine (TeMPD). Both chain ends of the 6FDA-TeMPD polyimide were end-capped with either UV-reacted groups, 1,1-bis(acryloyloxy methyl) ethyl isocyanate (BEI) group or p-aminostyrene (PAS) group. The two types of telechelic polyimide membranes, 6FDA-TeMPD-BEI and 6FDA-TeMPD-PAS, were formed with UV irradiation from the low-viscosity solutions using the solvent-casting method. The base polyimide membrane was soluble in tetrahydrofuran, whereas both UV-cured telechelic polyimide membranes were partly insoluble in it. This result suggested that both telechelic polyimides reacted at the polymer chain ends through UV irradiation. The density values of the UV-cured membranes were almost the sam...