Preparation And Characterization Of Anion Exchange Membranes Based On Polysulfone

Polysulfone (PSF) is a kind of thermoplastic polymer materials containing aromatic sulfone in its main chain. It exhibits high chemical stability, good mechanical properties, and is obtained easily with low cost. Preparation of high-performance ion-exchange membranes based on PSF by chemical modification have been attracted many attentions.Anion exchange membranes were prepared based on PSF in this work. The chloromethylation of PSF was performed using non-toxic trimethylchlorosilane. The influences on the chloromethylation reaction as well as the chloromethylation degree of PSF were investigated. The anionic conducting material of quaternary phosphonium PSF (QPPSF) was synthesized from chloromethylated PSF via phosphonium quaternization. Preparation of QPPSF membranes was studied by investigation the influences of the various solvents and cross-linking agents. The conditions for the membrane casting including the temperature, the evaporation rate of the solvents, and the atmosphere were also investigated. Characterizations of the QPPSF membrane were made and its properties were tested.It is difficult to obtain a membrane of QPPSF with acceptable mechanical strength. The membrane of the anionic conducting quaternized polysulfone (QAPSF) exhibits excellent mechanical properties, which was thus used to prepare hybrid membranes of QPPSF/QAPSF. Characterizations of the hybrid membranes including the water uptake, swelling, ionic exchange capacity, conductivity and mechanical properties were made. The results indicated that the presence of QAPSF resulted in a good mechanical strength of the hybrid membrane. However, the conductivity of QPPSF/QAPSF membranes was lower than that of the pristine QPPSF membranes.